Despite the abundance of different frameworks and ways to develop front-end applications, there are fundamental principles that are used everywhere and practically do not change. They concern splitting the application into layers (for example, MVC), separating the state and organizing it, working with texts, and controlling form data. This course teaches how to build an application architecture without being tied to specific solutions and their features.
<!DOCTYPE html>
<html class="h-100" data-bs-theme="light" data-mantine-color-scheme="light" lang="en" prefix="og: https://ogp.me/ns#">
<head>
<meta content="width=device-width, initial-scale=1.0" name="viewport">
<meta content="IE=Edge" http-equiv="X-UA-Compatible">
<link crossorigin="true" href="https://cdn.hexlet.io" rel="preconnect">
<meta content="aa2vrdtq64dub8knuf83lwywit311w" name="facebook-domain-verification">
<link href="/favicon.ico" rel="icon" sizes="any">
<link href="/favicon.svg" rel="icon" type="image/svg+xml">
<link href="/apple-touch-icon.png" rel="apple-touch-icon">
<link href="/manifest.webmanifest" rel="manifest">
<script>
//<![CDATA[
window.gon={};gon.ym_counter="25559621";gon.is_bot=true;gon.applications={};gon.current_user={"id":null,"last_viewed_notification_id":null,"email":null,"state":null,"first_name":"","last_name":"","current_program":null,"current_team":null,"full_name":"","guest":true,"can_use_paid_features":false,"is_hexlet_employee":false,"sanitized_phone_number":"","can_subscribe":true,"can_renew_education":false};gon.token="Z_fzV5Ig7ZdSmisW_WVfd8T4GE8SPCd-yE4cWB41CSU0MZ5hs0vWdzWQ1P5P-2i2yFKWFN4iPXJqy9ZLU-nW_g";gon.locale="en";gon.language="en";gon.theme="light";gon.rails_env="production";gon.mobile=false;gon.google={"analytics_key":"UA-1360700-51","optimize_key":"GTM-5QDVFPF"};gon.captcha={"google_v3_site_key":"6LenGbgZAAAAAM7HbrDbn5JlizCSzPcS767c9vaY","yandex_site_key":"ysc1_Vyob5ZPPUdPBsu0ykt8bVFdzsfpoVjQChLGl2b4g19647a89","verification_failed":null};gon.social_signin=false;gon.typoreporter_google_form_id="1FAIpQLScNwxM8rjQRRWqW5G6dn6-0NvLUblFemy7EvA9VsJ7Ov5wXqA";
//]]>
</script>
<meta charset="utf-8">
<title>Course «JS: Frontend architecture»: online education</title>
<meta name="description" content="Take the JS: Frontend architecture course at the Hexlet online school. Experienced mentors, practice on simulators, open-source projects in your portfolio. Individual and group online learning at Hexlet.">
<link rel="canonical" href="https://hexlet.io/courses/js-frontend-architecture">
<meta property="og:description" content="Take the JS: Frontend architecture course at the Hexlet online school. Experienced mentors, practice on simulators, open-source projects in your portfolio. Individual and group online learning at Hexlet.
">
<meta property="og:title" content="Course «JS: Frontend architecture»: online education
">
<meta property="og:url" content="https://hexlet.io/courses/js-frontend-architecture">
<meta name="csrf-param" content="authenticity_token" />
<meta name="csrf-token" content="PdKy38VNrM4OeTXOVIAfOC838nVwzbjdDGdN_6SjOnBuFN_p5CaXLmlzyibmHij5I518LrzTotGu4ofs6X_lqw" />
<script src="/vite/assets/inertia-CgrHVkgd.js" crossorigin="anonymous" type="module"></script><link rel="modulepreload" href="/vite/assets/chunk-DsPFFUou.js" as="script" crossorigin="anonymous">
<link rel="modulepreload" href="/vite/assets/preload-helper-C1cfMHAs.js" as="script" crossorigin="anonymous">
<link rel="modulepreload" href="/vite/assets/init-0bhwJkNI.js" as="script" crossorigin="anonymous">
<link rel="modulepreload" href="/vite/assets/ahoy-BXKrsWjp.js" as="script" crossorigin="anonymous">
<link rel="modulepreload" href="/vite/assets/analytics-Du9ljYPK.js" as="script" crossorigin="anonymous">
<link rel="modulepreload" href="/vite/assets/ErrorFallbackBlock-V3hfk_CP.js" as="script" crossorigin="anonymous">
<link rel="modulepreload" href="/vite/assets/RootLayout-CUZzAr0T.js" as="script" crossorigin="anonymous">
<link rel="modulepreload" href="/vite/assets/Surface-DbDKujDz.js" as="script" crossorigin="anonymous">
<link rel="modulepreload" href="/vite/assets/gon-B-jV56Ol.js" as="script" crossorigin="anonymous">
<link rel="modulepreload" href="/vite/assets/mantine-DOJkeu70.js" as="script" crossorigin="anonymous">
<link rel="modulepreload" href="/vite/assets/utils-ClTF9s_T.js" as="script" crossorigin="anonymous">
<link rel="modulepreload" href="/vite/assets/routes-mvvEXZQ8.js" as="script" crossorigin="anonymous">
<link rel="modulepreload" href="/vite/assets/index.esm-DATLpQdV.js" as="script" crossorigin="anonymous">
<link rel="modulepreload" href="/vite/assets/Modal-BhY0AP_c.js" as="script" crossorigin="anonymous">
<link rel="modulepreload" href="/vite/assets/Textarea-P1s4q94S.js" as="script" crossorigin="anonymous">
<link rel="modulepreload" href="/vite/assets/exports-BsSGGK2I.js" as="script" crossorigin="anonymous">
<link rel="modulepreload" href="/vite/assets/dayjs.min-Bfba02I7.js" as="script" crossorigin="anonymous">
<link rel="modulepreload" href="/vite/assets/client-CYyKzrjQ.js" as="script" crossorigin="anonymous">
<link rel="modulepreload" href="/vite/assets/react-dom-SJZekO2j.js" as="script" crossorigin="anonymous">
<link rel="modulepreload" href="/vite/assets/useTranslation-bo78L81P.js" as="script" crossorigin="anonymous">
<link rel="modulepreload" href="/vite/assets/compiler-runtime-BhqaZ6vG.js" as="script" crossorigin="anonymous">
<link rel="modulepreload" href="/vite/assets/jsx-runtime-DlXMvSuQ.js" as="script" crossorigin="anonymous">
<link rel="modulepreload" href="/vite/assets/react-CFtMU8gd.js" as="script" crossorigin="anonymous">
<link rel="stylesheet" href="/vite/assets/application-BhDYOUva.css" />
<script src="/vite/assets/application-ZyVHkzwO.js" crossorigin="anonymous" type="module"></script><link rel="modulepreload" href="/vite/assets/chunk-DsPFFUou.js" as="script" crossorigin="anonymous">
<link rel="modulepreload" href="/vite/assets/autocomplete-BokUl44d.js" as="script" crossorigin="anonymous">
<link rel="modulepreload" href="/vite/assets/routes-mvvEXZQ8.js" as="script" crossorigin="anonymous">
<link rel="modulepreload" href="/vite/assets/createPopper-gQnwoPhY.js" as="script" crossorigin="anonymous">
<link rel="modulepreload" href="/vite/assets/js.cookie-CB1F2-VC.js" as="script" crossorigin="anonymous"><link rel="stylesheet" href="/vite/assets/application-BhDYOUva.css" media="screen" />
<!-- Google Tag Manager - deferred -->
<script>
// dataLayer stub сразу — пуши работают до загрузки скрипта
window.dataLayer = window.dataLayer || [];
// Сам скрипт — отложенно после load
window.addEventListener('load', function() {
setTimeout(function() {
dataLayer.push({'gtm.start': new Date().getTime(), event: 'gtm.js'});
var j = document.createElement('script');
j.async = true;
j.src = 'https://www.googletagmanager.com/gtm.js?id=GTM-WK88TH';
document.head.appendChild(j);
}, 1500);
});
</script>
<!-- End Google Tag Manager -->
</head>
<body>
<!-- Google Tag Manager (noscript) -->
<noscript>
<iframe height="0" src="https://www.googletagmanager.com/ns.html?id=GTM-WK88TH" style="display:none;visibility:hidden" width="0"></iframe>
</noscript>
<!-- End Google Tag Manager (noscript) -->
<header class="sticky-top bg-body">
<nav class="navbar navbar-expand-lg">
<div class="container-xxl">
<a class="navbar-brand" href="/"><img alt="Hexlet logo" height="24" src="https://hexlet.io/vite/assets/logo_en_light-FS-yL6XB.svg" width="96">
</a><button aria-controls="collapsable" aria-expanded="false" aria-label="Menu" class="navbar-toggler border-0 mb-0 mt-1" data-bs-target="#collapsable" data-bs-toggle="collapse">
<span class="navbar-toggler-icon"></span>
</button>
<div class="collapse navbar-collapse" id="collapsable">
<ul class="navbar-nav mb-lg-0 mt-lg-1">
<li class="nav-item dropdown">
<button aria-haspopup class="btn nav-link" data-bs-toggle="dropdown" type="button">
All courses
<span class="bi bi-chevron-down align-middle ms-1"></span>
</button>
<ul class="dropdown-menu">
<li>
<a class="dropdown-item d-flex py-2" href="/courses"><div class="fw-bold me-auto">Everything</div>
<div class="text-muted">8</div>
</a></li>
<li>
<hr class="dropdown-divider">
</li>
<li class="dropdown-item">
<b>Popular categories</b>
</li>
<li>
<a class="dropdown-item py-2" href="/courses_backend-development">Backend Development
</a></li>
<li>
<a class="dropdown-item py-2" href="/courses_devops">DevOps
</a></li>
<li>
<a class="dropdown-item py-2" href="/courses_frontend-development">Frontend Development
</a></li>
<li>
<a class="dropdown-item py-2" href="/courses_testing">Testing
</a></li>
<li>
<hr class="dropdown-divider">
</li>
<li class="dropdown-item">
<b>Popular courses</b>
</li>
<li>
<a class="dropdown-item py-2" href="/programs/frontend">Frontend Developer
</a></li>
</ul>
</li>
<li class="nav-item dropdown">
<button aria-haspopup class="btn nav-link" data-bs-toggle="dropdown" type="button">
About Hexlet
<span class="bi bi-chevron-down align-middle"></span>
</button>
<ul class="dropdown-menu bg-body">
<li>
<a class="dropdown-item py-2" href="/pages/about">About company
</a></li>
<li>
<a class="dropdown-item py-2" href="/blog">Blog
</a></li>
<li>
<span class="dropdown-item py-2 external-link" data-href="https://special.hexlet.io/hse-research" role="button"><span class="translation_missing" title="translation missing: en.layouts.header.results">Results</span>
</span></li>
<li>
<span class="dropdown-item py-2 external-link" data-href="https://career.hexlet.io" role="button"><span class="translation_missing" title="translation missing: en.layouts.header.career">Career</span>
</span></li>
<li>
<a class="dropdown-item py-2" href="/testimonials">Testimonials
</a></li>
<li>
<span class="dropdown-item py-2 external-link" data-href="https://t.me/hexlet_help_bot" role="button"><span class="translation_missing" title="translation missing: en.layouts.header.support">Support</span>
</span></li>
<li>
<span class="dropdown-item py-2 external-link" data-href="https://special.hexlet.io/referal-program/?promo_creative=priglasite-druzei&promo_name=referal-program&promo_position=promo_position&promo_start=010724&promo_type=link" role="button"><span class="translation_missing" title="translation missing: en.layouts.header.referal_program">Referal Program</span>
</span></li>
<li>
<span class="dropdown-item py-2 external-link" data-href="https://special.hexlet.io/certificate" role="button"><span class="translation_missing" title="translation missing: en.layouts.header.certificates">Certificates</span>
</span></li>
<li>
<span class="dropdown-item py-2 external-link" data-href="https://hh.ru/employer/4307094" role="button"><span class="translation_missing" title="translation missing: en.layouts.header.vacancies">Vacancies</span>
</span></li>
<li>
<span class="dropdown-item d-flex external-link" rel="noopener noreferrer nofollow" data-href="https://b2b.hexlet.io" data-target="_blank" role="button"><span class="translation_missing" title="translation missing: en.layouts.header.teams">Teams</span>
</span></li>
<li>
<span class="dropdown-item d-flex external-link" rel="noopener noreferrer nofollow" data-href="https://hexly.ru/" data-target="_blank" role="button"><span class="translation_missing" title="translation missing: en.layouts.header.college">College</span>
</span></li>
<li>
<span class="dropdown-item d-flex external-link" rel="noopener noreferrer nofollow" data-href="https://hexlyschool.ru/" data-target="_blank" role="button"><span class="translation_missing" title="translation missing: en.layouts.header.private_school">Private School</span>
</span></li>
</ul>
</li>
</ul>
<ul class="navbar-nav flex-lg-row align-items-lg-center gap-2 ms-auto">
<li>
<a class="nav-link" aria-label="Switch theme" href="/theme/switch?new_theme=dark"><span aria-hidden="true" class="bi bi-moon"></span>
</a></li>
<li>
<span data-target="_self" class="nav-link external-link" data-href="/u/new" role="button"><span>Sign up</span>
</span></li>
<li>
<span data-target="_self" class="nav-link external-link" data-href="https://hexlet.io/session/new" role="button"><span>Sign in</span>
</span></li>
</ul>
</div>
</div>
</nav>
</header>
<div class="x-container-xxxl">
</div>
<main class="mb-6 min-vh-100 h-100">
<link rel="preload" as="image" href="https://hexlet.io/rails/active_storage/representations/proxy/eyJfcmFpbHMiOnsiZGF0YSI6MTIzNTMsInB1ciI6ImJsb2JfaWQifX0=--f1948fb0c5a45a6d76671a1a32b8cf6f0b53ee57/eyJfcmFpbHMiOnsiZGF0YSI6eyJmb3JtYXQiOiJ3ZWJwIiwicmVzaXplX3RvX2xpbWl0IjpbNDAwLDQwMF0sInNhdmVyIjp7InF1YWxpdHkiOjg1fX0sInB1ciI6InZhcmlhdGlvbiJ9fQ==--5b6f46dacd1af664f27558553a58076185091823/Software%20code%20testing-cuate.png"/><link rel="preload" as="image" href="https://hexlet.io/rails/active_storage/representations/proxy/eyJfcmFpbHMiOnsiZGF0YSI6MTIzNTAsInB1ciI6ImJsb2JfaWQifX0=--4c31372fe7c51ddbc0ef0d54fe47eaba88a2b04b/eyJfcmFpbHMiOnsiZGF0YSI6eyJmb3JtYXQiOiJ3ZWJwIiwicmVzaXplX3RvX2xpbWl0IjpbNDAwLDQwMF0sInNhdmVyIjp7InF1YWxpdHkiOjg1fX0sInB1ciI6InZhcmlhdGlvbiJ9fQ==--5b6f46dacd1af664f27558553a58076185091823/Programmer-rafiki.png"/><link rel="preload" as="image" href="/vite/assets/development-BVihs_d5.png"/><link rel="preload" as="image" href="https://hexlet.io/rails/active_storage/representations/proxy/eyJfcmFpbHMiOnsiZGF0YSI6MTQ1MzYsInB1ciI6ImJsb2JfaWQifX0=--dbc1b7632e854ecb29e9ae81aebfdaa60b98b9de/eyJfcmFpbHMiOnsiZGF0YSI6eyJmb3JtYXQiOiJqcGciLCJyZXNpemVfdG9fZmlsbCI6WzYwMCw0MDBdfSwicHVyIjoidmFyaWF0aW9uIn19--39ba06fa99226096df9fc6bb31f84e1d29ea98e9/image.png"/><div id="app" data-page="{"component":"web/courses/show","props":{"errors":{},"locale":"en","language":"en","httpsHost":"https://hexlet.io","host":"hexlet.io","colorScheme":"light","auth":{"user":{"id":null,"last_viewed_notification_id":null,"email":null,"state":null,"first_name":"","last_name":"","current_program":null,"current_team":null,"full_name":"","guest":true,"can_use_paid_features":false,"is_hexlet_employee":false,"sanitized_phone_number":"","can_subscribe":true,"can_renew_education":false}},"cloudflareTurnstileSiteKey":"0x4AAAAAAA15KmeFXzd2H0Xo","vkIdClientId":"51586979","yandexIdClientId":null,"formAuthToken":"zPxzPmI7AnwkSnQpefTvqnLW_ihfa9ZQLIpapZk6-J6fOh4IQ1A5nENAi8HLathrfnxwc5N1zFyOD5C21OYnRQ","course":{"start_lesson":{"exercise":null,"units":[{"id":7757,"name":"theory","url":"/courses/js-frontend-architecture/lessons/intro/theory_unit"}],"links":[],"ordered_units":[{"id":7757,"name":"theory","url":"/courses/js-frontend-architecture/lessons/intro/theory_unit"}],"id":3455,"slug":"intro","state":"approved","name":"Introduction","course_order":100,"goal":"Explore the course and its objectives","self_study":null,"theory_video_provider":null,"theory_video_uid":null,"theory":"Knowing how to use JavaScript and how to work with the DOM are the basic building blocks on which everything else is built. You need them to create applications that work well, are easily maintained, and can be extended, but they're not the only thing. There's actually much more. Working with the DOM without having a deep understanding of how code is organized will cause nothing but problems.\n\nThis approach still works for developers who make small widgets, for example, in jQuery. But as soon we get to making a full-fledged frontend application, the approaches that were used to create widgets will immediately prove themselves a disadvantage. Just add a dozen or so handlers and the code will turn into a load of unsupported spaghetti.\n\nFortunately, learning how to build architecture for frontend applications isn't that difficult. Moreover, all these approaches were developed decades ago, literally when the first visual interfaces first appeared. It's hard to believe now, but it was invented quite a long time ago.\n\nMoreover, these approaches go virtually unchanged from framework to framework. That's why in this course, they'll be given in \"raw\" form, without reference to any frameworks. Here, we'll tell you about and explorer the underlying approaches that are instrumental when it comes to architecture.\n\nThe main subjects in this course are: \n\n* State management and organization\n* Model-View-Controller\n* Controlled and uncontrolled forms\n* Automata-based programming\n* Working with texts. Internationalization, localization, and pluralization\n\n## Preparation\n\nArchitectural issues come up for developers when they have worked with the code, at least a little, and see how quickly it becomes unsupported. This course is no exception, and it was created with slightly more experienced students in mind. This experience can be gained independently outside of Hexlet, as well as on Hexlet as part of the profession [Frontend Developer](https://hexlet.io/programs/frontend). In terms of the program, this course comes after learning the JavaScript language itself, doing a few projects, and taking the course on the DOM API. If you don't know frontend development to this extent, we recommend you take this course later and carry on the profession without missing any practical assignments.\n"},"id":333,"slug":"js-frontend-architecture","challenges_count":2,"name":"JS: Frontend architecture","allow_indexing":true,"state":"approved","course_state":"finished","pricing_type":"paid","description":"Despite the abundance of different frameworks and ways to develop front-end applications, there are fundamental principles that are used everywhere and practically do not change. They concern splitting the application into layers (for example, MVC), separating the state and organizing it, working with texts, and controlling form data. This course teaches how to build an application architecture without being tied to specific solutions and their features.","kind":"advanced","updated_at":"2026-02-13T16:42:50.173Z","language":"javascript","duration_cache":47040,"skills":["Build modular and easily extensible front-end applications","Correctly separate applications into layers and build dependencies between them","Structure the state of the application in an optimal way","Use the theory of automata to describe the ongoing processes in the code"],"keywords":[],"lessons_count":11,"cover":"https://hexlet.io/rails/active_storage/representations/proxy/eyJfcmFpbHMiOnsiZGF0YSI6MTQ1MzYsInB1ciI6ImJsb2JfaWQifX0=--dbc1b7632e854ecb29e9ae81aebfdaa60b98b9de/eyJfcmFpbHMiOnsiZGF0YSI6eyJmb3JtYXQiOiJqcGciLCJyZXNpemVfdG9fZmlsbCI6WzYwMCw0MDBdfSwicHVyIjoidmFyaWF0aW9uIn19--39ba06fa99226096df9fc6bb31f84e1d29ea98e9/image.png"},"courseMember":null,"questionsCount":19,"exercisesCount":10,"lessons":[{"ordered_units":[{"id":7757,"name":"theory","url":"/courses/js-frontend-architecture/lessons/intro/theory_unit"}],"id":3455,"slug":"intro","state":"approved","name":"Introduction","course_order":100,"goal":"Explore the course and its objectives","exercise_id":null},{"ordered_units":[{"id":7758,"name":"theory","url":"/courses/js-frontend-architecture/lessons/state/theory_unit"},{"id":7781,"name":"exercise","url":"/courses/js-frontend-architecture/lessons/state/exercise_unit"}],"id":3456,"slug":"state","state":"approved","name":"Application state","course_order":200,"goal":"Explore the concept of separating program data from presentation (page appearance)","exercise_id":2274},{"ordered_units":[{"id":7759,"name":"theory","url":"/courses/js-frontend-architecture/lessons/complex-state/theory_unit"},{"id":8035,"name":"quiz","url":"/courses/js-frontend-architecture/lessons/complex-state/quiz_unit"},{"id":7782,"name":"exercise","url":"/courses/js-frontend-architecture/lessons/complex-state/exercise_unit"}],"id":3457,"slug":"complex-state","state":"approved","name":"Complex state","course_order":250,"goal":"Learn best practices for organizing the structure of a complex state","exercise_id":2275},{"ordered_units":[{"id":7760,"name":"theory","url":"/courses/js-frontend-architecture/lessons/rendering/theory_unit"},{"id":7783,"name":"exercise","url":"/courses/js-frontend-architecture/lessons/rendering/exercise_unit"}],"id":3458,"slug":"rendering","state":"approved","name":"Rendering state","course_order":280,"goal":"Explore different strategies for updating a view based on data","exercise_id":2276},{"ordered_units":[{"id":7761,"name":"theory","url":"/courses/js-frontend-architecture/lessons/ui-state/theory_unit"},{"id":7784,"name":"exercise","url":"/courses/js-frontend-architecture/lessons/ui-state/exercise_unit"}],"id":3459,"slug":"ui-state","state":"approved","name":"UI State","course_order":290,"goal":"Explore the concept of UI state and learn how to properly organize it without mixing it with application data","exercise_id":2277},{"ordered_units":[{"id":7762,"name":"theory","url":"/courses/js-frontend-architecture/lessons/processes/theory_unit"},{"id":8036,"name":"quiz","url":"/courses/js-frontend-architecture/lessons/processes/quiz_unit"},{"id":7785,"name":"exercise","url":"/courses/js-frontend-architecture/lessons/processes/exercise_unit"}],"id":3460,"slug":"processes","state":"approved","name":"Processes and automata that describe them","course_order":300,"goal":"Learn to see root processes and build a state based on them","exercise_id":2278},{"ordered_units":[{"id":7763,"name":"theory","url":"/courses/js-frontend-architecture/lessons/shape-of-state/theory_unit"},{"id":7786,"name":"exercise","url":"/courses/js-frontend-architecture/lessons/shape-of-state/exercise_unit"}],"id":3461,"slug":"shape-of-state","state":"approved","name":"Data normalization","course_order":350,"goal":"Learn the basic principles of data normalization","exercise_id":2279},{"ordered_units":[{"id":7764,"name":"theory","url":"/courses/js-frontend-architecture/lessons/mvc/theory_unit"},{"id":8037,"name":"quiz","url":"/courses/js-frontend-architecture/lessons/mvc/quiz_unit"},{"id":7787,"name":"exercise","url":"/courses/js-frontend-architecture/lessons/mvc/exercise_unit"}],"id":3462,"slug":"mvc","state":"approved","name":"MVC","course_order":400,"goal":"Learn the Model-View-Controller architecture","exercise_id":2280},{"ordered_units":[{"id":7765,"name":"theory","url":"/courses/js-frontend-architecture/lessons/forms/theory_unit"},{"id":8038,"name":"quiz","url":"/courses/js-frontend-architecture/lessons/forms/quiz_unit"},{"id":7788,"name":"exercise","url":"/courses/js-frontend-architecture/lessons/forms/exercise_unit"}],"id":3463,"slug":"forms","state":"approved","name":"Form State","course_order":500,"goal":"Learn about different ways to control form state","exercise_id":2281},{"ordered_units":[{"id":7766,"name":"theory","url":"/courses/js-frontend-architecture/lessons/i18n/theory_unit"},{"id":8039,"name":"quiz","url":"/courses/js-frontend-architecture/lessons/i18n/quiz_unit"},{"id":8090,"name":"exercise","url":"/courses/js-frontend-architecture/lessons/i18n/exercise_unit"}],"id":3464,"slug":"i18n","state":"approved","name":"Organization of interface texts","course_order":600,"goal":"Learn how to properly store, process, and display inscriptions and texts on the site","exercise_id":2282},{"ordered_units":[{"id":7767,"name":"theory","url":"/courses/js-frontend-architecture/lessons/initialization/theory_unit"},{"id":8040,"name":"quiz","url":"/courses/js-frontend-architecture/lessons/initialization/quiz_unit"},{"id":8091,"name":"exercise","url":"/courses/js-frontend-architecture/lessons/initialization/exercise_unit"}],"id":3465,"slug":"initialization","state":"approved","name":"Application initialization","course_order":700,"goal":"Learn how to properly separate applications into different stages of work","exercise_id":2283}],"challenges":[{"exercise":{"id":2273,"slug":"js_frontend_architecture_form_state_exercise","name":"Form state","state":"active","kind":"challenge","language":"javascript","locale":"en","has_web_view":true,"has_test_view":false,"reviewable":true,"readme":"## app.js\n\nImplement the form logic for adding new todo entries:\n\n- the form supports input validation (mandatory field, minimum 3, maximum 30 characters)\n- while loading a new record, the form fields and the submit button should be blocked\n\nThe application has a server that accepts POST requests with the body `{ todo: { name } }` to */todos*. Define the server response format yourself.\n\n## view.js\n\nImplement the logic responsible for the view layer in the application.\n\n### Examples\n\nInitial HTML:\n\n```html\n<form id=\"todo-form\" class=\"form-inline mb-3\">\n <div class=\"form-group\">\n <input id=\"todo-input\" type=\"text\" class=\"form-control mr-2\" name=\"name\" placeholder=\"New todo\">\n </div>\n <button id=\"todo-submit\" class=\"btn btn-primary\" type=\"submit\">Save</button>\n</form>\n<ul id=\"todos\" class=\"list-group\">\n</ul>\n```\n\nWhen you try to send an entry that is too short:\n\n```html\n<form id=\"todo-form\" class=\"form-inline mb-3\">\n <div class=\"form-group\">\n <input id=\"todo-input\" type=\"text\" class=\"form-control mr-2 is-invalid\" name=\"name\" placeholder=\"New todo\">\n <div class=\"invalid-feedback\">this must be at least 3 characters</div>\n </div>\n <button id=\"todo-submit\" class=\"btn btn-primary\" type=\"submit\">Save</button>\n</form>\n<ul id=\"todos\" class=\"list-group\">\n</ul>\n```\n\nAfter successful submission:\n\n```html\n<form id=\"todo-form\" class=\"form-inline mb-3\">\n <div class=\"form-group\">\n <input id=\"todo-input\" type=\"text\" class=\"form-control mr-2\" name=\"name\" placeholder=\"New todo\">\n </div>\n <button id=\"todo-submit\" class=\"btn btn-primary\" type=\"submit\">Save</button>\n</form>\n<ul id=\"todos\" class=\"list-group\">\n <li>read books</li>\n</ul>\n```\n\n### Hints\n\n- to handle application errors (for example, network errors), you can use the [toast component](https://getbootstrap.com/docs/4.5/components/toasts/), there is a stub in the markup.\n- [yup](https://github.com/jquense/yup) validation functions are asynchronous, but their synchronous versions can be used. \n- [onchange](https://github.com/sindresorhus/on-change)\n","prepared_readme":"## app.js\n\nImplement the form logic for adding new todo entries:\n\n- the form supports input validation (mandatory field, minimum 3, maximum 30 characters)\n- while loading a new record, the form fields and the submit button should be blocked\n\nThe application has a server that accepts POST requests with the body `{ todo: { name } }` to */todos*. Define the server response format yourself.\n\n## view.js\n\nImplement the logic responsible for the view layer in the application.\n\n### Examples\n\nInitial HTML:\n\n```html\n<form id=\"todo-form\" class=\"form-inline mb-3\">\n <div class=\"form-group\">\n <input id=\"todo-input\" type=\"text\" class=\"form-control mr-2\" name=\"name\" placeholder=\"New todo\">\n </div>\n <button id=\"todo-submit\" class=\"btn btn-primary\" type=\"submit\">Save</button>\n</form>\n<ul id=\"todos\" class=\"list-group\">\n</ul>\n```\n\nWhen you try to send an entry that is too short:\n\n```html\n<form id=\"todo-form\" class=\"form-inline mb-3\">\n <div class=\"form-group\">\n <input id=\"todo-input\" type=\"text\" class=\"form-control mr-2 is-invalid\" name=\"name\" placeholder=\"New todo\">\n <div class=\"invalid-feedback\">this must be at least 3 characters</div>\n </div>\n <button id=\"todo-submit\" class=\"btn btn-primary\" type=\"submit\">Save</button>\n</form>\n<ul id=\"todos\" class=\"list-group\">\n</ul>\n```\n\nAfter successful submission:\n\n```html\n<form id=\"todo-form\" class=\"form-inline mb-3\">\n <div class=\"form-group\">\n <input id=\"todo-input\" type=\"text\" class=\"form-control mr-2\" name=\"name\" placeholder=\"New todo\">\n </div>\n <button id=\"todo-submit\" class=\"btn btn-primary\" type=\"submit\">Save</button>\n</form>\n<ul id=\"todos\" class=\"list-group\">\n <li>read books</li>\n</ul>\n```\n\n### Hints\n\n- to handle application errors (for example, network errors), you can use the [toast component](https://getbootstrap.com/docs/4.5/components/toasts/), there is a stub in the markup.\n- [yup](https://github.com/jquense/yup) validation functions are asynchronous, but their synchronous versions can be used. \n- [onchange](https://github.com/sindresorhus/on-change)\n","has_solution":true,"entity_name":"Form state"},"course":{"start_lesson":{"exercise":null,"units":[{"id":7757,"name":"theory","url":"/courses/js-frontend-architecture/lessons/intro/theory_unit"}],"links":[],"ordered_units":[{"id":7757,"name":"theory","url":"/courses/js-frontend-architecture/lessons/intro/theory_unit"}],"id":3455,"slug":"intro","state":"approved","name":"Introduction","course_order":100,"goal":"Explore the course and its objectives","self_study":null,"theory_video_provider":null,"theory_video_uid":null,"theory":"Knowing how to use JavaScript and how to work with the DOM are the basic building blocks on which everything else is built. You need them to create applications that work well, are easily maintained, and can be extended, but they're not the only thing. There's actually much more. Working with the DOM without having a deep understanding of how code is organized will cause nothing but problems.\n\nThis approach still works for developers who make small widgets, for example, in jQuery. But as soon we get to making a full-fledged frontend application, the approaches that were used to create widgets will immediately prove themselves a disadvantage. Just add a dozen or so handlers and the code will turn into a load of unsupported spaghetti.\n\nFortunately, learning how to build architecture for frontend applications isn't that difficult. Moreover, all these approaches were developed decades ago, literally when the first visual interfaces first appeared. It's hard to believe now, but it was invented quite a long time ago.\n\nMoreover, these approaches go virtually unchanged from framework to framework. That's why in this course, they'll be given in \"raw\" form, without reference to any frameworks. Here, we'll tell you about and explorer the underlying approaches that are instrumental when it comes to architecture.\n\nThe main subjects in this course are: \n\n* State management and organization\n* Model-View-Controller\n* Controlled and uncontrolled forms\n* Automata-based programming\n* Working with texts. Internationalization, localization, and pluralization\n\n## Preparation\n\nArchitectural issues come up for developers when they have worked with the code, at least a little, and see how quickly it becomes unsupported. This course is no exception, and it was created with slightly more experienced students in mind. This experience can be gained independently outside of Hexlet, as well as on Hexlet as part of the profession [Frontend Developer](https://hexlet.io/programs/frontend). In terms of the program, this course comes after learning the JavaScript language itself, doing a few projects, and taking the course on the DOM API. If you don't know frontend development to this extent, we recommend you take this course later and carry on the profession without missing any practical assignments.\n"},"id":333,"slug":"js-frontend-architecture","challenges_count":2,"name":"JS: Frontend architecture","allow_indexing":true,"state":"approved","course_state":"finished","pricing_type":"paid","description":"Despite the abundance of different frameworks and ways to develop front-end applications, there are fundamental principles that are used everywhere and practically do not change. They concern splitting the application into layers (for example, MVC), separating the state and organizing it, working with texts, and controlling form data. This course teaches how to build an application architecture without being tied to specific solutions and their features.","kind":"advanced","updated_at":"2026-02-13T16:42:50.173Z","language":"javascript","duration_cache":47040,"skills":["Build modular and easily extensible front-end applications","Correctly separate applications into layers and build dependencies between them","Structure the state of the application in an optimal way","Use the theory of automata to describe the ongoing processes in the code"],"keywords":[],"lessons_count":11,"cover":"https://hexlet.io/rails/active_storage/representations/proxy/eyJfcmFpbHMiOnsiZGF0YSI6MTQ1MzYsInB1ciI6ImJsb2JfaWQifX0=--dbc1b7632e854ecb29e9ae81aebfdaa60b98b9de/eyJfcmFpbHMiOnsiZGF0YSI6eyJmb3JtYXQiOiJqcGciLCJyZXNpemVfdG9fZmlsbCI6WzYwMCw0MDBdfSwicHVyIjoidmFyaWF0aW9uIn19--39ba06fa99226096df9fc6bb31f84e1d29ea98e9/image.png"},"id":656,"slug":"js_frontend_architecture_form_state_exercise","percent_of_success":"-"},{"exercise":{"id":2272,"slug":"js_frontend_architecture_table_sort_exercise","name":"Table sorting","state":"active","kind":"challenge","language":"javascript","locale":"en","has_web_view":true,"has_test_view":false,"reviewable":true,"readme":"In this exercise, you will implement the grid. In interfaces, this is the name of a list displayed in a tabular form and allowing you to perform various actions on it, for example, sorting.\n\nAs data, you need to take the `document.location` object, which contains information about the browser. Incomplete output example:\n\n| Name (Asc) | Value (Unsorted) |\n|--------------|----------------------------|\n| host | localhost |\n| pathname | / |\n\nYou only need to display those properties that satisfy the conditions:\n\n* Not functions\n* Not objects\n* Not empty\n\nBy default, the output is in alphabetical order by property name. This order can be changed by clicking on the heading. If there is a click on another column, then sorting by it occurs (in ascending order). Clicking again changes the sort order. If the comparison reveals that the values are the same, the order of the rows is determined by sorting by the next colum.\n\n```html\n<div class=\"container m-3\">\n <table class=\"table\">\n <tbody>\n <tr>\n <th><a href=\"\">Name (Asc)</a></th>\n <th><a href=\"\">Value (Unsorted)</a></th>\n </tr>\n <tr>\n <td>host</td>\n <td>localhost</td>\n </tr>\n <tr>\n <td>hostname</td>\n <td>localhost</td>\n </tr>\n <tr>\n <td>href</td>\n <td>http://localhost/</td>\n </tr>\n <tr>\n <td>origin</td>\n <td>http://localhost</td>\n </tr>\n <tr>\n <td>pathname</td>\n <td>/</td>\n </tr>\n <tr>\n <td>protocol</td>\n <td>http:</td>\n </tr>\n </tbody>\n </table>\n</div>\n```\n\nNext to each heading, in brackets, is the status of the column. There are three in total:\n\n* Not sorted\n* Direct\n* Reverse\n\nSorting can only be done on one column at a time.\n\n## src/application.js\n\nExport the default function that implements all the required logic. Texts must be provided through the _i18next_ library.\n\n## Hints\n\n* String comparison [localeCompare](https://developer.mozilla.org/en/docs/Web/JavaScript/Reference/Global_Objects/String/localeCompare)\n* Translations can be nested: `I18n.t('key', { value: I18n.t('another key') })`\n* All the properties of an object (including inherited) can be got through a loop _for..in_\n","prepared_readme":"In this exercise, you will implement the grid. In interfaces, this is the name of a list displayed in a tabular form and allowing you to perform various actions on it, for example, sorting.\n\nAs data, you need to take the `document.location` object, which contains information about the browser. Incomplete output example:\n\n| Name (Asc) | Value (Unsorted) |\n|--------------|----------------------------|\n| host | localhost |\n| pathname | / |\n\nYou only need to display those properties that satisfy the conditions:\n\n* Not functions\n* Not objects\n* Not empty\n\nBy default, the output is in alphabetical order by property name. This order can be changed by clicking on the heading. If there is a click on another column, then sorting by it occurs (in ascending order). Clicking again changes the sort order. If the comparison reveals that the values are the same, the order of the rows is determined by sorting by the next colum.\n\n```html\n<div class=\"container m-3\">\n <table class=\"table\">\n <tbody>\n <tr>\n <th><a href=\"\">Name (Asc)</a></th>\n <th><a href=\"\">Value (Unsorted)</a></th>\n </tr>\n <tr>\n <td>host</td>\n <td>localhost</td>\n </tr>\n <tr>\n <td>hostname</td>\n <td>localhost</td>\n </tr>\n <tr>\n <td>href</td>\n <td>http://localhost/</td>\n </tr>\n <tr>\n <td>origin</td>\n <td>http://localhost</td>\n </tr>\n <tr>\n <td>pathname</td>\n <td>/</td>\n </tr>\n <tr>\n <td>protocol</td>\n <td>http:</td>\n </tr>\n </tbody>\n </table>\n</div>\n```\n\nNext to each heading, in brackets, is the status of the column. There are three in total:\n\n* Not sorted\n* Direct\n* Reverse\n\nSorting can only be done on one column at a time.\n\n## src/application.js\n\nExport the default function that implements all the required logic. Texts must be provided through the _i18next_ library.\n\n## Hints\n\n* String comparison [localeCompare](https://developer.mozilla.org/en/docs/Web/JavaScript/Reference/Global_Objects/String/localeCompare)\n* Translations can be nested: `I18n.t('key', { value: I18n.t('another key') })`\n* All the properties of an object (including inherited) can be got through a loop _for..in_\n","has_solution":true,"entity_name":"Table sorting"},"course":{"start_lesson":{"exercise":null,"units":[{"id":7757,"name":"theory","url":"/courses/js-frontend-architecture/lessons/intro/theory_unit"}],"links":[],"ordered_units":[{"id":7757,"name":"theory","url":"/courses/js-frontend-architecture/lessons/intro/theory_unit"}],"id":3455,"slug":"intro","state":"approved","name":"Introduction","course_order":100,"goal":"Explore the course and its objectives","self_study":null,"theory_video_provider":null,"theory_video_uid":null,"theory":"Knowing how to use JavaScript and how to work with the DOM are the basic building blocks on which everything else is built. You need them to create applications that work well, are easily maintained, and can be extended, but they're not the only thing. There's actually much more. Working with the DOM without having a deep understanding of how code is organized will cause nothing but problems.\n\nThis approach still works for developers who make small widgets, for example, in jQuery. But as soon we get to making a full-fledged frontend application, the approaches that were used to create widgets will immediately prove themselves a disadvantage. Just add a dozen or so handlers and the code will turn into a load of unsupported spaghetti.\n\nFortunately, learning how to build architecture for frontend applications isn't that difficult. Moreover, all these approaches were developed decades ago, literally when the first visual interfaces first appeared. It's hard to believe now, but it was invented quite a long time ago.\n\nMoreover, these approaches go virtually unchanged from framework to framework. That's why in this course, they'll be given in \"raw\" form, without reference to any frameworks. Here, we'll tell you about and explorer the underlying approaches that are instrumental when it comes to architecture.\n\nThe main subjects in this course are: \n\n* State management and organization\n* Model-View-Controller\n* Controlled and uncontrolled forms\n* Automata-based programming\n* Working with texts. Internationalization, localization, and pluralization\n\n## Preparation\n\nArchitectural issues come up for developers when they have worked with the code, at least a little, and see how quickly it becomes unsupported. This course is no exception, and it was created with slightly more experienced students in mind. This experience can be gained independently outside of Hexlet, as well as on Hexlet as part of the profession [Frontend Developer](https://hexlet.io/programs/frontend). In terms of the program, this course comes after learning the JavaScript language itself, doing a few projects, and taking the course on the DOM API. If you don't know frontend development to this extent, we recommend you take this course later and carry on the profession without missing any practical assignments.\n"},"id":333,"slug":"js-frontend-architecture","challenges_count":2,"name":"JS: Frontend architecture","allow_indexing":true,"state":"approved","course_state":"finished","pricing_type":"paid","description":"Despite the abundance of different frameworks and ways to develop front-end applications, there are fundamental principles that are used everywhere and practically do not change. They concern splitting the application into layers (for example, MVC), separating the state and organizing it, working with texts, and controlling form data. This course teaches how to build an application architecture without being tied to specific solutions and their features.","kind":"advanced","updated_at":"2026-02-13T16:42:50.173Z","language":"javascript","duration_cache":47040,"skills":["Build modular and easily extensible front-end applications","Correctly separate applications into layers and build dependencies between them","Structure the state of the application in an optimal way","Use the theory of automata to describe the ongoing processes in the code"],"keywords":[],"lessons_count":11,"cover":"https://hexlet.io/rails/active_storage/representations/proxy/eyJfcmFpbHMiOnsiZGF0YSI6MTQ1MzYsInB1ciI6ImJsb2JfaWQifX0=--dbc1b7632e854ecb29e9ae81aebfdaa60b98b9de/eyJfcmFpbHMiOnsiZGF0YSI6eyJmb3JtYXQiOiJqcGciLCJyZXNpemVfdG9fZmlsbCI6WzYwMCw0MDBdfSwicHVyIjoidmFyaWF0aW9uIn19--39ba06fa99226096df9fc6bb31f84e1d29ea98e9/image.png"},"id":655,"slug":"js_frontend_architecture_table_sort_exercise","percent_of_success":"-"}],"recommendedLandings":[{"stack":{"id":15,"slug":"frontend","title":"Frontend Developer","audience":"for_beginners","start_type":"anytime","pricing_model":"purchase","priority":"low","kind":"profession","state":"published","stack_state":"finished","order":1,"duration_in_months":10},"id":22,"slug":"frontend","title":"Frontend Developer","subtitle":"","subtitle_for_lists":"","locale":"en","current":true,"duration_in_months_text":"10 months","stack_slug":"frontend","price_text":"from $49","duration_text":"10 months","cover_list_variant":"https://hexlet.io/rails/active_storage/representations/proxy/eyJfcmFpbHMiOnsiZGF0YSI6MTIzNTMsInB1ciI6ImJsb2JfaWQifX0=--f1948fb0c5a45a6d76671a1a32b8cf6f0b53ee57/eyJfcmFpbHMiOnsiZGF0YSI6eyJmb3JtYXQiOiJ3ZWJwIiwicmVzaXplX3RvX2xpbWl0IjpbNDAwLDQwMF0sInNhdmVyIjp7InF1YWxpdHkiOjg1fX0sInB1ciI6InZhcmlhdGlvbiJ9fQ==--5b6f46dacd1af664f27558553a58076185091823/Software%20code%20testing-cuate.png"},{"stack":{"id":137,"slug":"js-react-development","title":"React","audience":"for_programmers","start_type":"anytime","pricing_model":"subscription","priority":"high","kind":"track","state":"published","stack_state":"finished","order":null,"duration_in_months":2},"id":234,"slug":"js-react-development","title":"React","subtitle":"Skill in building fast, user-friendly interfaces that boosts chances of landing exciting roles at top tech companies","subtitle_for_lists":"","locale":"en","current":true,"duration_in_months_text":"2 months","stack_slug":"js-react-development","price_text":"from $49","duration_text":"2 months","cover_list_variant":"https://hexlet.io/rails/active_storage/representations/proxy/eyJfcmFpbHMiOnsiZGF0YSI6MTIzNTAsInB1ciI6ImJsb2JfaWQifX0=--4c31372fe7c51ddbc0ef0d54fe47eaba88a2b04b/eyJfcmFpbHMiOnsiZGF0YSI6eyJmb3JtYXQiOiJ3ZWJwIiwicmVzaXplX3RvX2xpbWl0IjpbNDAwLDQwMF0sInNhdmVyIjp7InF1YWxpdHkiOjg1fX0sInB1ciI6InZhcmlhdGlvbiJ9fQ==--5b6f46dacd1af664f27558553a58076185091823/Programmer-rafiki.png"}]},"url":"/courses/js-frontend-architecture","version":"1656487db0d1dd5f33634fe1070e57e55135cbeb","encryptHistory":false,"clearHistory":false}"><style data-mantine-styles="true">:root, :host{--mantine-font-family: Arial, sans-serif;--mantine-font-family-headings: Arial, sans-serif;--mantine-heading-font-weight: normal;--mantine-radius-default: 0rem;--mantine-primary-color-filled: var(--mantine-color-indigo-filled);--mantine-primary-color-filled-hover: var(--mantine-color-indigo-filled-hover);--mantine-primary-color-light: var(--mantine-color-indigo-light);--mantine-primary-color-light-hover: var(--mantine-color-indigo-light-hover);--mantine-primary-color-light-color: var(--mantine-color-indigo-light-color);--mantine-spacing-xxl: calc(4rem * var(--mantine-scale));--mantine-font-size-xs: 12px;--mantine-font-size-sm: 14px;--mantine-font-size-md: 16px;--mantine-font-size-lg: clamp(16.0000px, calc(15.2727px + 0.2273vw), 18.0000px);--mantine-font-size-xl: clamp(16.0000px, calc(14.5455px + 0.4545vw), 20.0000px);--mantine-font-size-display-3: clamp(32.0000px, calc(26.1818px + 1.8182vw), 48.0000px);--mantine-font-size-display-2: clamp(36.0000px, calc(25.8182px + 3.1818vw), 64.0000px);--mantine-font-size-display-1: clamp(40.0000px, calc(25.4545px + 4.5455vw), 80.0000px);--mantine-font-size-h1: clamp(28.0000px, calc(23.6364px + 1.3636vw), 40.0000px);--mantine-font-size-h2: clamp(24.0000px, calc(21.0909px + 0.9091vw), 32.0000px);--mantine-font-size-h3: clamp(20.0000px, calc(17.0909px + 0.9091vw), 28.0000px);--mantine-font-size-h4: clamp(16.0000px, calc(13.0909px + 0.9091vw), 24.0000px);--mantine-font-size-h5: clamp(16.0000px, calc(14.5455px + 0.4545vw), 20.0000px);--mantine-font-size-h6: 1rem;--mantine-primary-color-0: var(--mantine-color-indigo-0);--mantine-primary-color-1: var(--mantine-color-indigo-1);--mantine-primary-color-2: var(--mantine-color-indigo-2);--mantine-primary-color-3: var(--mantine-color-indigo-3);--mantine-primary-color-4: var(--mantine-color-indigo-4);--mantine-primary-color-5: var(--mantine-color-indigo-5);--mantine-primary-color-6: var(--mantine-color-indigo-6);--mantine-primary-color-7: var(--mantine-color-indigo-7);--mantine-primary-color-8: var(--mantine-color-indigo-8);--mantine-primary-color-9: var(--mantine-color-indigo-9);--mantine-color-red-0: #ffeaea;--mantine-color-red-1: #fed4d4;--mantine-color-red-2: #f4a7a8;--mantine-color-red-3: #ec7878;--mantine-color-red-4: #e55050;--mantine-color-red-5: #e03131;--mantine-color-red-6: #e02829;--mantine-color-red-7: #c71a1c;--mantine-color-red-8: #b21218;--mantine-color-red-9: #9c0411;--mantine-color-violet-0: #fce9ff;--mantine-color-violet-1: #f1cfff;--mantine-color-violet-2: #e09bff;--mantine-color-violet-3: #d16fff;--mantine-color-violet-4: #be37fe;--mantine-color-violet-5: #b51afe;--mantine-color-violet-6: #b009ff;--mantine-color-violet-7: #9b00e4;--mantine-color-violet-8: #8a00cc;--mantine-color-violet-9: #7800b3;--mantine-color-indigo-0: #edecff;--mantine-color-indigo-1: #d6d5fe;--mantine-color-indigo-2: #aaa9f4;--mantine-color-indigo-3: #7b79eb;--mantine-color-indigo-4: #5451e4;--mantine-color-indigo-5: #3b37e0;--mantine-color-indigo-6: #2d2adf;--mantine-color-indigo-7: #1f1ec7;--mantine-color-indigo-8: #1819b2;--mantine-color-indigo-9: #0c149e;--mantine-color-cyan-0: #dffdff;--mantine-color-cyan-1: #caf5ff;--mantine-color-cyan-2: #99e8ff;--mantine-color-cyan-3: #64daff;--mantine-color-cyan-4: #3ccffe;--mantine-color-cyan-5: #24c8fe;--mantine-color-cyan-6: #00c2ff;--mantine-color-cyan-7: #00ade4;--mantine-color-cyan-8: #009acd;--mantine-color-cyan-9: #0085b5;--mantine-color-green-0: #e9fdec;--mantine-color-green-1: #d7f6dc;--mantine-color-green-2: #b0eab9;--mantine-color-green-3: #86df94;--mantine-color-green-4: #62d574;--mantine-color-green-5: #4ccf5f;--mantine-color-green-6: #3fcc54;--mantine-color-green-7: #2fb344;--mantine-color-green-8: #25a03b;--mantine-color-green-9: #138a2e;--mantine-color-yellow-0: #fff7e2;--mantine-color-yellow-1: #ffeecd;--mantine-color-yellow-2: #ffdc9c;--mantine-color-yellow-3: #ffc966;--mantine-color-yellow-4: #feb93a;--mantine-color-yellow-5: #feae1e;--mantine-color-yellow-6: #ffa90f;--mantine-color-yellow-8: #ca8200;--mantine-color-yellow-9: #af7000;--mantine-h1-font-size: clamp(28.0000px, calc(23.6364px + 1.3636vw), 40.0000px);--mantine-h1-font-weight: normal;--mantine-h2-font-size: clamp(24.0000px, calc(21.0909px + 0.9091vw), 32.0000px);--mantine-h2-font-weight: normal;--mantine-h3-font-size: clamp(20.0000px, calc(17.0909px + 0.9091vw), 28.0000px);--mantine-h3-font-weight: normal;--mantine-h4-font-size: clamp(16.0000px, calc(13.0909px + 0.9091vw), 24.0000px);--mantine-h4-font-weight: normal;--mantine-h5-font-size: clamp(16.0000px, calc(14.5455px + 0.4545vw), 20.0000px);--mantine-h5-font-weight: normal;--mantine-h6-font-size: 1rem;--mantine-h6-font-weight: normal;}
:root[data-mantine-color-scheme="dark"], :host([data-mantine-color-scheme="dark"]){--mantine-color-anchor: var(--mantine-color-text);--mantine-color-dimmed: #495057;--mantine-color-dark-filled: var(--mantine-color-dark-5);--mantine-color-dark-filled-hover: var(--mantine-color-dark-6);--mantine-color-dark-light: rgba(105, 105, 105, 0.15);--mantine-color-dark-light-hover: rgba(105, 105, 105, 0.2);--mantine-color-dark-light-color: var(--mantine-color-dark-0);--mantine-color-dark-outline: var(--mantine-color-dark-1);--mantine-color-dark-outline-hover: rgba(184, 184, 184, 0.05);--mantine-color-gray-filled: var(--mantine-color-gray-5);--mantine-color-gray-filled-hover: var(--mantine-color-gray-6);--mantine-color-gray-light: rgba(222, 226, 230, 0.15);--mantine-color-gray-light-hover: rgba(222, 226, 230, 0.2);--mantine-color-gray-light-color: var(--mantine-color-gray-0);--mantine-color-gray-outline: var(--mantine-color-gray-1);--mantine-color-gray-outline-hover: rgba(241, 243, 245, 0.05);--mantine-color-red-filled: var(--mantine-color-red-5);--mantine-color-red-filled-hover: var(--mantine-color-red-6);--mantine-color-red-light: rgba(236, 120, 120, 0.15);--mantine-color-red-light-hover: rgba(236, 120, 120, 0.2);--mantine-color-red-light-color: var(--mantine-color-red-0);--mantine-color-red-outline: var(--mantine-color-red-1);--mantine-color-red-outline-hover: rgba(254, 212, 212, 0.05);--mantine-color-pink-filled: var(--mantine-color-pink-5);--mantine-color-pink-filled-hover: var(--mantine-color-pink-6);--mantine-color-pink-light: rgba(250, 162, 193, 0.15);--mantine-color-pink-light-hover: rgba(250, 162, 193, 0.2);--mantine-color-pink-light-color: var(--mantine-color-pink-0);--mantine-color-pink-outline: var(--mantine-color-pink-1);--mantine-color-pink-outline-hover: rgba(255, 222, 235, 0.05);--mantine-color-grape-filled: var(--mantine-color-grape-5);--mantine-color-grape-filled-hover: var(--mantine-color-grape-6);--mantine-color-grape-light: rgba(229, 153, 247, 0.15);--mantine-color-grape-light-hover: rgba(229, 153, 247, 0.2);--mantine-color-grape-light-color: var(--mantine-color-grape-0);--mantine-color-grape-outline: var(--mantine-color-grape-1);--mantine-color-grape-outline-hover: rgba(243, 217, 250, 0.05);--mantine-color-violet-filled: var(--mantine-color-violet-5);--mantine-color-violet-filled-hover: var(--mantine-color-violet-6);--mantine-color-violet-light: rgba(209, 111, 255, 0.15);--mantine-color-violet-light-hover: rgba(209, 111, 255, 0.2);--mantine-color-violet-light-color: var(--mantine-color-violet-0);--mantine-color-violet-outline: var(--mantine-color-violet-1);--mantine-color-violet-outline-hover: rgba(241, 207, 255, 0.05);--mantine-color-indigo-filled: var(--mantine-color-indigo-5);--mantine-color-indigo-filled-hover: var(--mantine-color-indigo-6);--mantine-color-indigo-light: rgba(123, 121, 235, 0.15);--mantine-color-indigo-light-hover: rgba(123, 121, 235, 0.2);--mantine-color-indigo-light-color: var(--mantine-color-indigo-0);--mantine-color-indigo-outline: var(--mantine-color-indigo-1);--mantine-color-indigo-outline-hover: rgba(214, 213, 254, 0.05);--mantine-color-blue-filled: var(--mantine-color-blue-5);--mantine-color-blue-filled-hover: var(--mantine-color-blue-6);--mantine-color-blue-light: rgba(116, 192, 252, 0.15);--mantine-color-blue-light-hover: rgba(116, 192, 252, 0.2);--mantine-color-blue-light-color: var(--mantine-color-blue-0);--mantine-color-blue-outline: var(--mantine-color-blue-1);--mantine-color-blue-outline-hover: rgba(208, 235, 255, 0.05);--mantine-color-cyan-filled: var(--mantine-color-cyan-5);--mantine-color-cyan-filled-hover: var(--mantine-color-cyan-6);--mantine-color-cyan-light: rgba(100, 218, 255, 0.15);--mantine-color-cyan-light-hover: rgba(100, 218, 255, 0.2);--mantine-color-cyan-light-color: var(--mantine-color-cyan-0);--mantine-color-cyan-outline: var(--mantine-color-cyan-1);--mantine-color-cyan-outline-hover: rgba(202, 245, 255, 0.05);--mantine-color-teal-filled: var(--mantine-color-teal-5);--mantine-color-teal-filled-hover: var(--mantine-color-teal-6);--mantine-color-teal-light: rgba(99, 230, 190, 0.15);--mantine-color-teal-light-hover: rgba(99, 230, 190, 0.2);--mantine-color-teal-light-color: var(--mantine-color-teal-0);--mantine-color-teal-outline: var(--mantine-color-teal-1);--mantine-color-teal-outline-hover: rgba(195, 250, 232, 0.05);--mantine-color-green-filled: var(--mantine-color-green-5);--mantine-color-green-filled-hover: var(--mantine-color-green-6);--mantine-color-green-light: rgba(134, 223, 148, 0.15);--mantine-color-green-light-hover: rgba(134, 223, 148, 0.2);--mantine-color-green-light-color: var(--mantine-color-green-0);--mantine-color-green-outline: var(--mantine-color-green-1);--mantine-color-green-outline-hover: rgba(215, 246, 220, 0.05);--mantine-color-lime-filled: var(--mantine-color-lime-5);--mantine-color-lime-filled-hover: var(--mantine-color-lime-6);--mantine-color-lime-light: rgba(192, 235, 117, 0.15);--mantine-color-lime-light-hover: rgba(192, 235, 117, 0.2);--mantine-color-lime-light-color: var(--mantine-color-lime-0);--mantine-color-lime-outline: var(--mantine-color-lime-1);--mantine-color-lime-outline-hover: rgba(233, 250, 200, 0.05);--mantine-color-yellow-filled: var(--mantine-color-yellow-5);--mantine-color-yellow-filled-hover: var(--mantine-color-yellow-6);--mantine-color-yellow-light: rgba(255, 201, 102, 0.15);--mantine-color-yellow-light-hover: rgba(255, 201, 102, 0.2);--mantine-color-yellow-light-color: var(--mantine-color-yellow-0);--mantine-color-yellow-outline: var(--mantine-color-yellow-1);--mantine-color-yellow-outline-hover: rgba(255, 238, 205, 0.05);--mantine-color-orange-filled: var(--mantine-color-orange-5);--mantine-color-orange-filled-hover: var(--mantine-color-orange-6);--mantine-color-orange-light: rgba(255, 192, 120, 0.15);--mantine-color-orange-light-hover: rgba(255, 192, 120, 0.2);--mantine-color-orange-light-color: var(--mantine-color-orange-0);--mantine-color-orange-outline: var(--mantine-color-orange-1);--mantine-color-orange-outline-hover: rgba(255, 232, 204, 0.05);--app-cta-gradient: linear-gradient(90deg, var(--mantine-color-blue-9) 0%, var(--mantine-color-cyan-7) 100%);--app-color-surface: #2e2e2e;}
:root[data-mantine-color-scheme="light"], :host([data-mantine-color-scheme="light"]){--mantine-color-anchor: var(--mantine-color-text);--mantine-color-dimmed: #495057;--mantine-color-red-light: rgba(224, 40, 41, 0.1);--mantine-color-red-light-hover: rgba(224, 40, 41, 0.12);--mantine-color-red-outline-hover: rgba(224, 40, 41, 0.05);--mantine-color-violet-light: rgba(176, 9, 255, 0.1);--mantine-color-violet-light-hover: rgba(176, 9, 255, 0.12);--mantine-color-violet-outline-hover: rgba(176, 9, 255, 0.05);--mantine-color-indigo-light: rgba(45, 42, 223, 0.1);--mantine-color-indigo-light-hover: rgba(45, 42, 223, 0.12);--mantine-color-indigo-outline-hover: rgba(45, 42, 223, 0.05);--mantine-color-cyan-light: rgba(0, 194, 255, 0.1);--mantine-color-cyan-light-hover: rgba(0, 194, 255, 0.12);--mantine-color-cyan-outline-hover: rgba(0, 194, 255, 0.05);--mantine-color-green-light: rgba(63, 204, 84, 0.1);--mantine-color-green-light-hover: rgba(63, 204, 84, 0.12);--mantine-color-green-outline-hover: rgba(63, 204, 84, 0.05);--mantine-color-yellow-light: rgba(255, 169, 15, 0.1);--mantine-color-yellow-light-hover: rgba(255, 169, 15, 0.12);--mantine-color-yellow-outline-hover: rgba(255, 169, 15, 0.05);--app-color-surface: #f1f3f5;--app-cta-gradient: linear-gradient(90deg, var(--mantine-color-blue-filled) 0%, var(--mantine-color-cyan-5) 100%);}</style><style data-mantine-styles="classes">@media (max-width: 35.99375em) {.mantine-visible-from-xs {display: none !important;}}@media (min-width: 36em) {.mantine-hidden-from-xs {display: none !important;}}@media (max-width: 47.99375em) {.mantine-visible-from-sm {display: none !important;}}@media (min-width: 48em) {.mantine-hidden-from-sm {display: none !important;}}@media (max-width: 61.99375em) {.mantine-visible-from-md {display: none !important;}}@media (min-width: 62em) {.mantine-hidden-from-md {display: none !important;}}@media (max-width: 74.99375em) {.mantine-visible-from-lg {display: none !important;}}@media (min-width: 75em) {.mantine-hidden-from-lg {display: none !important;}}@media (max-width: 87.99375em) {.mantine-visible-from-xl {display: none !important;}}@media (min-width: 88em) {.mantine-hidden-from-xl {display: none !important;}}</style><div style="--container-size:var(--container-size-lg);margin-top:var(--mantine-spacing-xl);height:100%" class="m_7485cace mantine-Container-root" data-size="lg" data-strategy="block"><style data-mantine-styles="inline">.__m__-_R_eub_{margin-bottom:var(--mantine-spacing-xs);}@media(min-width: 36em){.__m__-_R_eub_{margin-bottom:var(--mantine-spacing-xs);}}</style><div style="--group-gap:var(--mantine-spacing-md);--group-align:center;--group-justify:space-between;--group-wrap:wrap" class="m_4081bf90 mantine-Group-root __m__-_R_eub_"><style data-mantine-styles="inline">.__m__-_R_deub_{width:100%;}@media(min-width: 62em){.__m__-_R_deub_{width:66%;}}</style><div class="__m__-_R_deub_"><div style="--group-gap:var(--mantine-spacing-md);--group-align:center;--group-justify:start;--group-wrap:nowrap" class="m_4081bf90 mantine-Group-root"><h1 style="--title-fw:var(--mantine-h1-font-weight);--title-lh:var(--mantine-h1-line-height);--title-fz:var(--mantine-h1-font-size)" class="m_8a5d1357 mantine-Title-root" data-order="1">Course “JS: Frontend architecture”</h1></div></div></div><style data-mantine-styles="inline">.__m__-_R_1iub_{width:100%;}@media(min-width: 62em){.__m__-_R_1iub_{width:66%;}}</style><div style="margin-bottom:var(--mantine-spacing-xl)" class="__m__-_R_1iub_"><div style="margin-bottom:var(--mantine-spacing-lg)" class=""></div><div style="margin-top:var(--mantine-spacing-lg)" class="mantine-hidden-from-md"><div style="--stack-gap:var(--mantine-spacing-xs);--stack-align:stretch;--stack-justify:flex-start" class="m_6d731127 mantine-Stack-root"><a style="--button-height:var(--button-height-md);--button-padding-x:var(--button-padding-x-md);--button-fz:var(--mantine-font-size-md);--button-color:var(--mantine-color-white);text-decoration:none" class="mantine-focus-auto m_849cf0da mantine-focus-auto mantine-active m_77c9d27d mantine-Button-root m_87cf2631 mantine-UnstyledButton-root m_b6d8b162 mantine-Text-root mantine-Anchor-root" data-size="md" data-underline="hover" href="https://hexlet.io/subscription/new"><span class="m_80f1301b mantine-Button-inner"><span class="m_811560b9 mantine-Button-label">Subscribe</span></span></a><p style="color:var(--mantine-color-dimmed);font-size:var(--mantine-font-size-sm);text-align:center" class="mantine-focus-auto m_b6d8b162 mantine-Text-root">Access this and all courses with a subscription</p></div></div></div><style data-mantine-styles="inline">.__m__-_R_2iub_{--grid-gutter:var(--mantine-spacing-md);}</style><div class="m_410352e9 mantine-Grid-root __m__-_R_2iub_"><div class="m_dee7bd2f mantine-Grid-inner"><style data-mantine-styles="inline">.__m__-_R_dmiub_{--col-flex-grow:auto;--col-flex-basis:100%;--col-max-width:100%;}@media(min-width: 62em){.__m__-_R_dmiub_{--col-flex-grow:auto;--col-flex-basis:66.66666666666667%;--col-max-width:66.66666666666667%;}}</style><div class="m_96bdd299 mantine-Grid-col __m__-_R_dmiub_"><div style="margin-bottom:var(--mantine-spacing-xl);padding-inline:var(--mantine-spacing-xl);padding-block:var(--mantine-spacing-lg)" class="m_e615b15f mantine-Card-root m_1b7284a3 mantine-Paper-root" data-with-border="true"><p style="margin-bottom:var(--mantine-spacing-md);font-size:var(--mantine-font-size-h5);font-weight:bold" class="mantine-focus-auto m_b6d8b162 mantine-Text-root">What's included</p><style data-mantine-styles="inline">.__m__-_R_ajddmiub_{--sg-spacing-x:var(--mantine-spacing-xs);--sg-spacing-y:var(--mantine-spacing-xs);--sg-cols:1;}@media(min-width: 48em){.__m__-_R_ajddmiub_{--sg-cols:2;}}</style><div class="m_2415a157 mantine-SimpleGrid-root __m__-_R_ajddmiub_"><div style="align-items:center" class="m_8bffd616 mantine-Flex-root __m__-_R_1mqjddmiub_"><div style="--ti-size:var(--ti-size-xs);--ti-bg:transparent;--ti-color:var(--mantine-color-indigo-light-color);--ti-bd:calc(0.0625rem * var(--mantine-scale)) solid transparent;margin-inline-end:var(--mantine-spacing-xs);color:inherit" class="m_7341320d mantine-ThemeIcon-root" data-variant="transparent" data-size="xs"><svg xmlns="http://www.w3.org/2000/svg" width="24" height="24" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round" class="tabler-icon tabler-icon-check "><path d="M5 12l5 5l10 -10"></path></svg></div>11 lessons (video and/or text)</div><div style="align-items:center" class="m_8bffd616 mantine-Flex-root __m__-_R_2mqjddmiub_"><div style="--ti-size:var(--ti-size-xs);--ti-bg:transparent;--ti-color:var(--mantine-color-indigo-light-color);--ti-bd:calc(0.0625rem * var(--mantine-scale)) solid transparent;margin-inline-end:var(--mantine-spacing-xs);color:inherit" class="m_7341320d mantine-ThemeIcon-root" data-variant="transparent" data-size="xs"><svg xmlns="http://www.w3.org/2000/svg" width="24" height="24" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round" class="tabler-icon tabler-icon-check "><path d="M5 12l5 5l10 -10"></path></svg></div>10 exercises in the simulator</div><div style="align-items:center" class="m_8bffd616 mantine-Flex-root __m__-_R_3mqjddmiub_"><div style="--ti-size:var(--ti-size-xs);--ti-bg:transparent;--ti-color:var(--mantine-color-indigo-light-color);--ti-bd:calc(0.0625rem * var(--mantine-scale)) solid transparent;margin-inline-end:var(--mantine-spacing-xs);color:inherit" class="m_7341320d mantine-ThemeIcon-root" data-variant="transparent" data-size="xs"><svg xmlns="http://www.w3.org/2000/svg" width="24" height="24" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round" class="tabler-icon tabler-icon-check "><path d="M5 12l5 5l10 -10"></path></svg></div>19 verification tests</div><div style="align-items:center" class="m_8bffd616 mantine-Flex-root __m__-_R_4mqjddmiub_"><div style="--ti-size:var(--ti-size-xs);--ti-bg:transparent;--ti-color:var(--mantine-color-indigo-light-color);--ti-bd:calc(0.0625rem * var(--mantine-scale)) solid transparent;margin-inline-end:var(--mantine-spacing-xs);color:inherit" class="m_7341320d mantine-ThemeIcon-root" data-variant="transparent" data-size="xs"><svg xmlns="http://www.w3.org/2000/svg" width="24" height="24" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round" class="tabler-icon tabler-icon-check "><path d="M5 12l5 5l10 -10"></path></svg></div>Self-study tasks</div><div style="align-items:center" class="m_8bffd616 mantine-Flex-root __m__-_R_5mqjddmiub_"><div style="--ti-size:var(--ti-size-xs);--ti-bg:transparent;--ti-color:var(--mantine-color-indigo-light-color);--ti-bd:calc(0.0625rem * var(--mantine-scale)) solid transparent;margin-inline-end:var(--mantine-spacing-xs);color:inherit" class="m_7341320d mantine-ThemeIcon-root" data-variant="transparent" data-size="xs"><svg xmlns="http://www.w3.org/2000/svg" width="24" height="24" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round" class="tabler-icon tabler-icon-check "><path d="M5 12l5 5l10 -10"></path></svg></div>Extra materials</div><div style="align-items:center" class="m_8bffd616 mantine-Flex-root __m__-_R_6mqjddmiub_"><div style="--ti-size:var(--ti-size-xs);--ti-bg:transparent;--ti-color:var(--mantine-color-indigo-light-color);--ti-bd:calc(0.0625rem * var(--mantine-scale)) solid transparent;margin-inline-end:var(--mantine-spacing-xs);color:inherit" class="m_7341320d mantine-ThemeIcon-root" data-variant="transparent" data-size="xs"><svg xmlns="http://www.w3.org/2000/svg" width="24" height="24" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round" class="tabler-icon tabler-icon-plus "><path d="M12 5l0 14"></path><path d="M5 12l14 0"></path></svg></div>11 extended materials</div></div></div><div style="margin-bottom:var(--mantine-spacing-xl)" class=""><h2 style="--title-fw:var(--mantine-h2-font-weight);--title-lh:var(--mantine-h2-line-height);--title-fz:var(--mantine-h2-font-size);margin-bottom:var(--mantine-spacing-md)" class="m_8a5d1357 mantine-Title-root" data-order="2">Description</h2><div class="m_d08caa0 mantine-Typography-root"><p>Despite the abundance of different frameworks and ways to develop front-end applications, there are fundamental principles that are used everywhere and practically do not change. They concern splitting the application into layers (for example, MVC), separating the state and organizing it, working with texts, and controlling form data. This course teaches how to build an application architecture without being tied to specific solutions and their features.</p></div></div><div style="margin-bottom:var(--mantine-spacing-xl)" class=""><h2 style="--title-fw:var(--mantine-h2-font-weight);--title-lh:var(--mantine-h2-line-height);--title-fz:var(--mantine-h2-font-size);margin-bottom:var(--mantine-spacing-md)" class="m_8a5d1357 mantine-Title-root" data-order="2">You will learn</h2><ul class="m_abbac491 mantine-List-root" data-type="none"><li style="margin-bottom:var(--mantine-spacing-xs);line-height:var(--mantine-line-height-sm)" class="m_abb6bec2 mantine-List-item" data-with-icon="true" data-centered="true"><div class="m_75cd9f71 mantine-List-itemWrapper"><span class="m_60f83e5b mantine-List-itemIcon"><div style="--ti-size:var(--ti-size-xs);--ti-bg:transparent;--ti-color:var(--mantine-color-indigo-light-color);--ti-bd:calc(0.0625rem * var(--mantine-scale)) solid transparent;color:inherit" class="m_7341320d mantine-ThemeIcon-root" data-variant="transparent" data-size="xs"><svg xmlns="http://www.w3.org/2000/svg" width="24" height="24" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round" class="tabler-icon tabler-icon-plus "><path d="M12 5l0 14"></path><path d="M5 12l14 0"></path></svg></div></span><span class="mantine-List-itemLabel">Build modular and easily extensible front-end applications</span></div></li><li style="margin-bottom:var(--mantine-spacing-xs);line-height:var(--mantine-line-height-sm)" class="m_abb6bec2 mantine-List-item" data-with-icon="true" data-centered="true"><div class="m_75cd9f71 mantine-List-itemWrapper"><span class="m_60f83e5b mantine-List-itemIcon"><div style="--ti-size:var(--ti-size-xs);--ti-bg:transparent;--ti-color:var(--mantine-color-indigo-light-color);--ti-bd:calc(0.0625rem * var(--mantine-scale)) solid transparent;color:inherit" class="m_7341320d mantine-ThemeIcon-root" data-variant="transparent" data-size="xs"><svg xmlns="http://www.w3.org/2000/svg" width="24" height="24" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round" class="tabler-icon tabler-icon-plus "><path d="M12 5l0 14"></path><path d="M5 12l14 0"></path></svg></div></span><span class="mantine-List-itemLabel">Correctly separate applications into layers and build dependencies between them</span></div></li><li style="margin-bottom:var(--mantine-spacing-xs);line-height:var(--mantine-line-height-sm)" class="m_abb6bec2 mantine-List-item" data-with-icon="true" data-centered="true"><div class="m_75cd9f71 mantine-List-itemWrapper"><span class="m_60f83e5b mantine-List-itemIcon"><div style="--ti-size:var(--ti-size-xs);--ti-bg:transparent;--ti-color:var(--mantine-color-indigo-light-color);--ti-bd:calc(0.0625rem * var(--mantine-scale)) solid transparent;color:inherit" class="m_7341320d mantine-ThemeIcon-root" data-variant="transparent" data-size="xs"><svg xmlns="http://www.w3.org/2000/svg" width="24" height="24" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round" class="tabler-icon tabler-icon-plus "><path d="M12 5l0 14"></path><path d="M5 12l14 0"></path></svg></div></span><span class="mantine-List-itemLabel">Structure the state of the application in an optimal way</span></div></li><li style="margin-bottom:var(--mantine-spacing-xs);line-height:var(--mantine-line-height-sm)" class="m_abb6bec2 mantine-List-item" data-with-icon="true" data-centered="true"><div class="m_75cd9f71 mantine-List-itemWrapper"><span class="m_60f83e5b mantine-List-itemIcon"><div style="--ti-size:var(--ti-size-xs);--ti-bg:transparent;--ti-color:var(--mantine-color-indigo-light-color);--ti-bd:calc(0.0625rem * var(--mantine-scale)) solid transparent;color:inherit" class="m_7341320d mantine-ThemeIcon-root" data-variant="transparent" data-size="xs"><svg xmlns="http://www.w3.org/2000/svg" width="24" height="24" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round" class="tabler-icon tabler-icon-plus "><path d="M12 5l0 14"></path><path d="M5 12l14 0"></path></svg></div></span><span class="mantine-List-itemLabel">Use the theory of automata to describe the ongoing processes in the code</span></div></li></ul></div><div style="margin-bottom:var(--mantine-spacing-xl)" class=""><h2 style="--title-fw:var(--mantine-h2-font-weight);--title-lh:var(--mantine-h2-line-height);--title-fz:var(--mantine-h2-font-size);margin-bottom:var(--mantine-spacing-md)" class="m_8a5d1357 mantine-Title-root" data-order="2">Syllabus</h2><table style="--table-vertical-spacing:calc(0.4375rem * var(--mantine-scale))" class="m_b23fa0ef mantine-Table-table"><tbody class="m_b2404537 mantine-Table-tbody"><tr class="m_4e7aa4fd mantine-Table-tr" data-with-row-border="true"><td class="m_4e7aa4ef mantine-Table-td"><p style="font-size:var(--mantine-font-size-h4)" class="mantine-focus-auto m_b6d8b162 mantine-Text-root">1</p></td><td style="padding-block:var(--mantine-spacing-lg)" class="m_4e7aa4ef mantine-Table-td"><a style="color:inherit;font-size:var(--mantine-font-size-h5)" class="mantine-focus-auto m_849cf0da m_b6d8b162 mantine-Text-root mantine-Anchor-root" data-underline="hover" href="/courses/js-frontend-architecture/lessons/intro/theory_unit">Introduction</a><p style="color:var(--mantine-color-dimmed)" class="mantine-focus-auto m_b6d8b162 mantine-Text-root">Explore the course and its objectives</p></td></tr><tr class="m_4e7aa4fd mantine-Table-tr" data-with-row-border="true"><td class="m_4e7aa4ef mantine-Table-td"><p style="font-size:var(--mantine-font-size-h4)" class="mantine-focus-auto m_b6d8b162 mantine-Text-root">2</p></td><td style="padding-block:var(--mantine-spacing-lg)" class="m_4e7aa4ef mantine-Table-td"><a style="color:inherit;font-size:var(--mantine-font-size-h5)" class="mantine-focus-auto m_849cf0da m_b6d8b162 mantine-Text-root mantine-Anchor-root" data-underline="hover" href="/courses/js-frontend-architecture/lessons/state/theory_unit">Application state</a><p style="color:var(--mantine-color-dimmed)" class="mantine-focus-auto m_b6d8b162 mantine-Text-root">Explore the concept of separating program data from presentation (page appearance)</p></td></tr><tr class="m_4e7aa4fd mantine-Table-tr" data-with-row-border="true"><td class="m_4e7aa4ef mantine-Table-td"><p style="font-size:var(--mantine-font-size-h4)" class="mantine-focus-auto m_b6d8b162 mantine-Text-root">3</p></td><td style="padding-block:var(--mantine-spacing-lg)" class="m_4e7aa4ef mantine-Table-td"><a style="color:inherit;font-size:var(--mantine-font-size-h5)" class="mantine-focus-auto m_849cf0da m_b6d8b162 mantine-Text-root mantine-Anchor-root" data-underline="hover" href="/courses/js-frontend-architecture/lessons/complex-state/theory_unit">Complex state</a><p style="color:var(--mantine-color-dimmed)" class="mantine-focus-auto m_b6d8b162 mantine-Text-root">Learn best practices for organizing the structure of a complex state</p></td></tr><tr class="m_4e7aa4fd mantine-Table-tr" data-with-row-border="true"><td class="m_4e7aa4ef mantine-Table-td"><p style="font-size:var(--mantine-font-size-h4)" class="mantine-focus-auto m_b6d8b162 mantine-Text-root">4</p></td><td style="padding-block:var(--mantine-spacing-lg)" class="m_4e7aa4ef mantine-Table-td"><a style="color:inherit;font-size:var(--mantine-font-size-h5)" class="mantine-focus-auto m_849cf0da m_b6d8b162 mantine-Text-root mantine-Anchor-root" data-underline="hover" href="/courses/js-frontend-architecture/lessons/rendering/theory_unit">Rendering state</a><p style="color:var(--mantine-color-dimmed)" class="mantine-focus-auto m_b6d8b162 mantine-Text-root">Explore different strategies for updating a view based on data</p></td></tr><tr class="m_4e7aa4fd mantine-Table-tr" data-with-row-border="true"><td class="m_4e7aa4ef mantine-Table-td"><p style="font-size:var(--mantine-font-size-h4)" class="mantine-focus-auto m_b6d8b162 mantine-Text-root">5</p></td><td style="padding-block:var(--mantine-spacing-lg)" class="m_4e7aa4ef mantine-Table-td"><a style="color:inherit;font-size:var(--mantine-font-size-h5)" class="mantine-focus-auto m_849cf0da m_b6d8b162 mantine-Text-root mantine-Anchor-root" data-underline="hover" href="/courses/js-frontend-architecture/lessons/ui-state/theory_unit">UI State</a><p style="color:var(--mantine-color-dimmed)" class="mantine-focus-auto m_b6d8b162 mantine-Text-root">Explore the concept of UI state and learn how to properly organize it without mixing it with application data</p></td></tr><tr class="m_4e7aa4fd mantine-Table-tr" data-with-row-border="true"><td class="m_4e7aa4ef mantine-Table-td"><p style="font-size:var(--mantine-font-size-h4)" class="mantine-focus-auto m_b6d8b162 mantine-Text-root">6</p></td><td style="padding-block:var(--mantine-spacing-lg)" class="m_4e7aa4ef mantine-Table-td"><a style="color:inherit;font-size:var(--mantine-font-size-h5)" class="mantine-focus-auto m_849cf0da m_b6d8b162 mantine-Text-root mantine-Anchor-root" data-underline="hover" href="/courses/js-frontend-architecture/lessons/processes/theory_unit">Processes and automata that describe them</a><p style="color:var(--mantine-color-dimmed)" class="mantine-focus-auto m_b6d8b162 mantine-Text-root">Learn to see root processes and build a state based on them</p></td></tr><tr class="m_4e7aa4fd mantine-Table-tr" data-with-row-border="true"><td class="m_4e7aa4ef mantine-Table-td"><p style="font-size:var(--mantine-font-size-h4)" class="mantine-focus-auto m_b6d8b162 mantine-Text-root">7</p></td><td style="padding-block:var(--mantine-spacing-lg)" class="m_4e7aa4ef mantine-Table-td"><a style="color:inherit;font-size:var(--mantine-font-size-h5)" class="mantine-focus-auto m_849cf0da m_b6d8b162 mantine-Text-root mantine-Anchor-root" data-underline="hover" href="/courses/js-frontend-architecture/lessons/shape-of-state/theory_unit">Data normalization</a><p style="color:var(--mantine-color-dimmed)" class="mantine-focus-auto m_b6d8b162 mantine-Text-root">Learn the basic principles of data normalization</p></td></tr><tr class="m_4e7aa4fd mantine-Table-tr" data-with-row-border="true"><td class="m_4e7aa4ef mantine-Table-td"><p style="font-size:var(--mantine-font-size-h4)" class="mantine-focus-auto m_b6d8b162 mantine-Text-root">8</p></td><td style="padding-block:var(--mantine-spacing-lg)" class="m_4e7aa4ef mantine-Table-td"><a style="color:inherit;font-size:var(--mantine-font-size-h5)" class="mantine-focus-auto m_849cf0da m_b6d8b162 mantine-Text-root mantine-Anchor-root" data-underline="hover" href="/courses/js-frontend-architecture/lessons/mvc/theory_unit">MVC</a><p style="color:var(--mantine-color-dimmed)" class="mantine-focus-auto m_b6d8b162 mantine-Text-root">Learn the Model-View-Controller architecture</p></td></tr><tr class="m_4e7aa4fd mantine-Table-tr" data-with-row-border="true"><td class="m_4e7aa4ef mantine-Table-td"><p style="font-size:var(--mantine-font-size-h4)" class="mantine-focus-auto m_b6d8b162 mantine-Text-root">9</p></td><td style="padding-block:var(--mantine-spacing-lg)" class="m_4e7aa4ef mantine-Table-td"><a style="color:inherit;font-size:var(--mantine-font-size-h5)" class="mantine-focus-auto m_849cf0da m_b6d8b162 mantine-Text-root mantine-Anchor-root" data-underline="hover" href="/courses/js-frontend-architecture/lessons/forms/theory_unit">Form State</a><p style="color:var(--mantine-color-dimmed)" class="mantine-focus-auto m_b6d8b162 mantine-Text-root">Learn about different ways to control form state</p></td></tr><tr class="m_4e7aa4fd mantine-Table-tr" data-with-row-border="true"><td class="m_4e7aa4ef mantine-Table-td"><p style="font-size:var(--mantine-font-size-h4)" class="mantine-focus-auto m_b6d8b162 mantine-Text-root">10</p></td><td style="padding-block:var(--mantine-spacing-lg)" class="m_4e7aa4ef mantine-Table-td"><a style="color:inherit;font-size:var(--mantine-font-size-h5)" class="mantine-focus-auto m_849cf0da m_b6d8b162 mantine-Text-root mantine-Anchor-root" data-underline="hover" href="/courses/js-frontend-architecture/lessons/i18n/theory_unit">Organization of interface texts</a><p style="color:var(--mantine-color-dimmed)" class="mantine-focus-auto m_b6d8b162 mantine-Text-root">Learn how to properly store, process, and display inscriptions and texts on the site</p></td></tr><tr class="m_4e7aa4fd mantine-Table-tr" data-with-row-border="true"><td class="m_4e7aa4ef mantine-Table-td"><p style="font-size:var(--mantine-font-size-h4)" class="mantine-focus-auto m_b6d8b162 mantine-Text-root">11</p></td><td style="padding-block:var(--mantine-spacing-lg)" class="m_4e7aa4ef mantine-Table-td"><a style="color:inherit;font-size:var(--mantine-font-size-h5)" class="mantine-focus-auto m_849cf0da m_b6d8b162 mantine-Text-root mantine-Anchor-root" data-underline="hover" href="/courses/js-frontend-architecture/lessons/initialization/theory_unit">Application initialization</a><p style="color:var(--mantine-color-dimmed)" class="mantine-focus-auto m_b6d8b162 mantine-Text-root">Learn how to properly separate applications into different stages of work</p></td></tr></tbody></table></div><div style="margin-bottom:var(--mantine-spacing-xl)" class=""><div style="--group-gap:var(--mantine-spacing-md);--group-align:center;--group-justify:flex-start;--group-wrap:wrap;margin-bottom:var(--mantine-spacing-md)" class="m_4081bf90 mantine-Group-root"><h2 style="--title-fw:var(--mantine-h2-font-weight);--title-lh:var(--mantine-h2-line-height);--title-fz:var(--mantine-h2-font-size)" class="m_8a5d1357 mantine-Title-root" data-order="2">Challenges</h2><button style="--ai-size:var(--ai-size-sm);--ai-bg:transparent;--ai-hover:transparent;--ai-color:var(--mantine-color-indigo-light-color);--ai-bd:calc(0.0625rem * var(--mantine-scale)) solid transparent;color:var(--mantine-color-dimmed)" class="mantine-focus-auto mantine-active m_8d3f4000 mantine-ActionIcon-root m_87cf2631 mantine-UnstyledButton-root" data-variant="transparent" data-size="sm" type="button" aria-haspopup="dialog" aria-expanded="false" id="mantine-_R_amtddmiub_-target"><span class="m_8d3afb97 mantine-ActionIcon-icon"><svg xmlns="http://www.w3.org/2000/svg" width="24" height="24" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round" class="tabler-icon tabler-icon-info-square-rounded "><path d="M12 9h.01"></path><path d="M11 12h1v4h1"></path><path d="M12 3c7.2 0 9 1.8 9 9c0 7.2 -1.8 9 -9 9c-7.2 0 -9 -1.8 -9 -9c0 -7.2 1.8 -9 9 -9"></path></svg></span></button></div><table style="--table-vertical-spacing:calc(0.4375rem * var(--mantine-scale))" class="m_b23fa0ef mantine-Table-table"><tbody class="m_b2404537 mantine-Table-tbody"><tr class="m_4e7aa4fd mantine-Table-tr" data-with-row-border="true"><td class="m_4e7aa4ef mantine-Table-td"><p class="mantine-focus-auto m_b6d8b162 mantine-Text-root">1</p></td><td class="m_4e7aa4ef mantine-Table-td"><p class="mantine-focus-auto m_b6d8b162 mantine-Text-root">Form state</p></td></tr><tr class="m_4e7aa4fd mantine-Table-tr" data-with-row-border="true"><td class="m_4e7aa4ef mantine-Table-td"><p class="mantine-focus-auto m_b6d8b162 mantine-Text-root">2</p></td><td class="m_4e7aa4ef mantine-Table-td"><p class="mantine-focus-auto m_b6d8b162 mantine-Text-root">Table sorting</p></td></tr></tbody></table></div><div class=""><h2 style="--title-fw:var(--mantine-h2-font-weight);--title-lh:var(--mantine-h2-line-height);--title-fz:var(--mantine-h2-font-size);margin-bottom:var(--mantine-spacing-md)" class="m_8a5d1357 mantine-Title-root" data-order="2">Recommended programs</h2><style data-mantine-styles="inline">.__m__-_R_avddmiub_{--carousel-slide-gap:var(--mantine-spacing-xs);--carousel-slide-size:70%;}@media(min-width: 36em){.__m__-_R_avddmiub_{--carousel-slide-gap:var(--mantine-spacing-xl);--carousel-slide-size:50%;}}</style><div style="--carousel-control-size:calc(2.5rem * var(--mantine-scale));--carousel-controls-offset:var(--mantine-spacing-sm);margin-bottom:var(--mantine-spacing-lg);padding-block:var(--mantine-spacing-sm);background:var(--app-color-surface)" class="m_17884d0f mantine-Carousel-root responsiveClassName" data-orientation="horizontal" data-include-gap-in-size="true"><div class="m_39bc3463 mantine-Carousel-controls" data-orientation="horizontal"><button class="mantine-focus-auto m_64f58e10 mantine-Carousel-control m_87cf2631 mantine-UnstyledButton-root" type="button" data-inactive="true" data-type="previous" tabindex="-1"><svg viewBox="0 0 15 15" fill="none" xmlns="http://www.w3.org/2000/svg" style="transform:rotate(90deg);width:calc(1rem * var(--mantine-scale));height:calc(1rem * var(--mantine-scale));display:block"><path d="M3.13523 6.15803C3.3241 5.95657 3.64052 5.94637 3.84197 6.13523L7.5 9.56464L11.158 6.13523C11.3595 5.94637 11.6759 5.95657 11.8648 6.15803C12.0536 6.35949 12.0434 6.67591 11.842 6.86477L7.84197 10.6148C7.64964 10.7951 7.35036 10.7951 7.15803 10.6148L3.15803 6.86477C2.95657 6.67591 2.94637 6.35949 3.13523 6.15803Z" fill="currentColor" fill-rule="evenodd" clip-rule="evenodd"></path></svg></button><button class="mantine-focus-auto m_64f58e10 mantine-Carousel-control m_87cf2631 mantine-UnstyledButton-root" type="button" data-inactive="true" data-type="next" tabindex="-1"><svg viewBox="0 0 15 15" fill="none" xmlns="http://www.w3.org/2000/svg" style="transform:rotate(-90deg);width:calc(1rem * var(--mantine-scale));height:calc(1rem * var(--mantine-scale));display:block"><path d="M3.13523 6.15803C3.3241 5.95657 3.64052 5.94637 3.84197 6.13523L7.5 9.56464L11.158 6.13523C11.3595 5.94637 11.6759 5.95657 11.8648 6.15803C12.0536 6.35949 12.0434 6.67591 11.842 6.86477L7.84197 10.6148C7.64964 10.7951 7.35036 10.7951 7.15803 10.6148L3.15803 6.86477C2.95657 6.67591 2.94637 6.35949 3.13523 6.15803Z" fill="currentColor" fill-rule="evenodd" clip-rule="evenodd"></path></svg></button></div><div class="m_a2dae653 mantine-Carousel-viewport" data-type="media"><div class="m_fcd81474 mantine-Carousel-container __m__-_R_avddmiub_" data-orientation="horizontal"><div class="m_d98df724 mantine-Carousel-slide" data-orientation="horizontal"><div tabindex="0" style="cursor:pointer;height:100%"><a style="text-decoration:none" class="mantine-focus-auto m_849cf0da m_b6d8b162 mantine-Text-root mantine-Anchor-root" data-underline="hover" href="/programs/frontend?promo_name=programs_list&promo_position=course&promo_creative=catalog_card&promo_type=card" target="_blank"><div style="height:100%" class="m_e615b15f mantine-Card-root m_1b7284a3 mantine-Paper-root" data-with-border="true"><div style="--group-gap:calc(0.25rem * var(--mantine-scale));--group-align:center;--group-justify:flex-start;--group-wrap:nowrap" class="m_4081bf90 mantine-Group-root"><span style="font-size:var(--mantine-font-size-sm)" class="mantine-focus-auto m_b6d8b162 mantine-Text-root">10 months</span><span class="mantine-focus-auto m_b6d8b162 mantine-Text-root">·</span><span style="font-size:var(--mantine-font-size-sm)" class="mantine-focus-auto m_b6d8b162 mantine-Text-root">For beginners</span></div><p style="margin-bottom:var(--mantine-spacing-sm);font-size:var(--mantine-font-size-h5);font-weight:bold" class="mantine-focus-auto m_b6d8b162 mantine-Text-root">Frontend Developer</p><p class="mantine-focus-auto m_b6d8b162 mantine-Text-root"></p><div style="margin-top:auto" class=""><div class="m_4451eb3a mantine-Center-root"><img style="opacity:0.8;width:70%" class="m_9e117634 mantine-Image-root mantine-visible-from-xs" src="https://hexlet.io/rails/active_storage/representations/proxy/eyJfcmFpbHMiOnsiZGF0YSI6MTIzNTMsInB1ciI6ImJsb2JfaWQifX0=--f1948fb0c5a45a6d76671a1a32b8cf6f0b53ee57/eyJfcmFpbHMiOnsiZGF0YSI6eyJmb3JtYXQiOiJ3ZWJwIiwicmVzaXplX3RvX2xpbWl0IjpbNDAwLDQwMF0sInNhdmVyIjp7InF1YWxpdHkiOjg1fX0sInB1ciI6InZhcmlhdGlvbiJ9fQ==--5b6f46dacd1af664f27558553a58076185091823/Software%20code%20testing-cuate.png" alt="Frontend Developer" loading="eager"/></div><div style="--group-gap:var(--mantine-spacing-md);--group-align:end;--group-justify:space-between;--group-wrap:wrap;margin-top:var(--mantine-spacing-xs)" class="m_4081bf90 mantine-Group-root"><p style="font-size:var(--mantine-font-size-xl)" class="mantine-focus-auto m_b6d8b162 mantine-Text-root">from $49</p><p style="font-size:var(--mantine-font-size-sm)" class="mantine-focus-auto m_b6d8b162 mantine-Text-root">Explore →</p></div></div></div></a></div></div><div class="m_d98df724 mantine-Carousel-slide" data-orientation="horizontal"><div tabindex="0" style="cursor:pointer;height:100%"><a style="text-decoration:none" class="mantine-focus-auto m_849cf0da m_b6d8b162 mantine-Text-root mantine-Anchor-root" data-underline="hover" href="/programs/js-react-development?promo_name=programs_list&promo_position=course&promo_creative=catalog_card&promo_type=card" target="_blank"><div style="height:100%" class="m_e615b15f mantine-Card-root m_1b7284a3 mantine-Paper-root" data-with-border="true"><div style="--group-gap:calc(0.25rem * var(--mantine-scale));--group-align:center;--group-justify:flex-start;--group-wrap:nowrap" class="m_4081bf90 mantine-Group-root"><span style="font-size:var(--mantine-font-size-sm)" class="mantine-focus-auto m_b6d8b162 mantine-Text-root">2 months</span><span class="mantine-focus-auto m_b6d8b162 mantine-Text-root">·</span><span style="font-size:var(--mantine-font-size-sm)" class="mantine-focus-auto m_b6d8b162 mantine-Text-root">For advanced</span></div><p style="margin-bottom:var(--mantine-spacing-sm);font-size:var(--mantine-font-size-h5);font-weight:bold" class="mantine-focus-auto m_b6d8b162 mantine-Text-root">React</p><p class="mantine-focus-auto m_b6d8b162 mantine-Text-root"></p><div style="margin-top:auto" class=""><div class="m_4451eb3a mantine-Center-root"><img style="opacity:0.8;width:70%" class="m_9e117634 mantine-Image-root mantine-visible-from-xs" src="https://hexlet.io/rails/active_storage/representations/proxy/eyJfcmFpbHMiOnsiZGF0YSI6MTIzNTAsInB1ciI6ImJsb2JfaWQifX0=--4c31372fe7c51ddbc0ef0d54fe47eaba88a2b04b/eyJfcmFpbHMiOnsiZGF0YSI6eyJmb3JtYXQiOiJ3ZWJwIiwicmVzaXplX3RvX2xpbWl0IjpbNDAwLDQwMF0sInNhdmVyIjp7InF1YWxpdHkiOjg1fX0sInB1ciI6InZhcmlhdGlvbiJ9fQ==--5b6f46dacd1af664f27558553a58076185091823/Programmer-rafiki.png" alt="React" loading="eager"/></div><div style="--group-gap:var(--mantine-spacing-md);--group-align:end;--group-justify:space-between;--group-wrap:wrap;margin-top:var(--mantine-spacing-xs)" class="m_4081bf90 mantine-Group-root"><p style="font-size:var(--mantine-font-size-xl)" class="mantine-focus-auto m_b6d8b162 mantine-Text-root">from $49</p><p style="font-size:var(--mantine-font-size-sm)" class="mantine-focus-auto m_b6d8b162 mantine-Text-root">Explore →</p></div></div></div></a></div></div><div class="m_d98df724 mantine-Carousel-slide" data-orientation="horizontal"><div tabindex="0" style="cursor:pointer;height:100%"><a style="text-decoration:none" class="mantine-focus-auto m_849cf0da m_b6d8b162 mantine-Text-root mantine-Anchor-root" data-underline="hover" href="/courses?promo_name=programs_list&promo_position=course&promo_creative=catalog_card&promo_type=card"><div style="height:100%" class="m_e615b15f mantine-Card-root m_1b7284a3 mantine-Paper-root" data-with-border="true"><h2 style="--title-fw:var(--mantine-h2-font-weight);--title-lh:var(--mantine-h2-line-height);--title-fz:var(--mantine-h2-font-size);margin-bottom:var(--mantine-spacing-md);font-size:var(--mantine-font-size-h3)" class="m_8a5d1357 mantine-Title-root" data-order="2" data-responsive="true">Catalog</h2><p style="margin-bottom:auto" class="mantine-focus-auto m_b6d8b162 mantine-Text-root">A complete list of available courses by direction</p><div style="margin-top:auto" class=""><div class="m_4451eb3a mantine-Center-root"><img style="opacity:0.8;width:70%" class="m_9e117634 mantine-Image-root mantine-visible-from-xs" src="/vite/assets/development-BVihs_d5.png" alt="Orientation"/></div></div></div></a></div></div></div></div></div></div></div><style data-mantine-styles="inline">.__m__-_R_lmiub_{--col-flex-grow:auto;--col-flex-basis:100%;--col-max-width:100%;}@media(min-width: 62em){.__m__-_R_lmiub_{--col-flex-grow:auto;--col-flex-basis:33.333333333333336%;--col-max-width:33.333333333333336%;}}</style><div class="m_96bdd299 mantine-Grid-col __m__-_R_lmiub_"><div style="--paper-shadow:var(--mantine-shadow-sm);margin-top:calc(-10.625rem * var(--mantine-scale));padding:0rem;position:sticky;top:calc(3.125rem * var(--mantine-scale))" class="m_e615b15f mantine-Card-root m_1b7284a3 mantine-Paper-root mantine-visible-from-md"><div class="m_e615b15f mantine-Card-root m_1b7284a3 mantine-Paper-root"><div style="margin-bottom:var(--mantine-spacing-md)" class="m_599a2148 mantine-Card-section" data-first-section="true"><img class="m_9e117634 mantine-Image-root" src="https://hexlet.io/rails/active_storage/representations/proxy/eyJfcmFpbHMiOnsiZGF0YSI6MTQ1MzYsInB1ciI6ImJsb2JfaWQifX0=--dbc1b7632e854ecb29e9ae81aebfdaa60b98b9de/eyJfcmFpbHMiOnsiZGF0YSI6eyJmb3JtYXQiOiJqcGciLCJyZXNpemVfdG9fZmlsbCI6WzYwMCw0MDBdfSwicHVyIjoidmFyaWF0aW9uIn19--39ba06fa99226096df9fc6bb31f84e1d29ea98e9/image.png" alt="Course Cover"/></div><ul style="margin-bottom:var(--mantine-spacing-md)" class="m_abbac491 mantine-List-root"><li style="line-height:var(--mantine-line-height-xl)" class="m_abb6bec2 mantine-List-item" data-with-icon="true" data-centered="true"><div class="m_75cd9f71 mantine-List-itemWrapper"><span class="m_60f83e5b mantine-List-itemIcon"><svg xmlns="http://www.w3.org/2000/svg" width="18" height="18" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round" class="tabler-icon tabler-icon-device-desktop-code "><path d="M12.5 16h-8.5a1 1 0 0 1 -1 -1v-10a1 1 0 0 1 1 -1h16a1 1 0 0 1 1 1v8"></path><path d="M7 20h4"></path><path d="M9 16v4"></path><path d="M20 21l2 -2l-2 -2"></path><path d="M17 17l-2 2l2 2"></path></svg></span><span class="mantine-List-itemLabel">Run code right in the browser</span></div></li><li style="line-height:var(--mantine-line-height-xl)" class="m_abb6bec2 mantine-List-item" data-with-icon="true" data-centered="true"><div class="m_75cd9f71 mantine-List-itemWrapper"><span class="m_60f83e5b mantine-List-itemIcon"><svg xmlns="http://www.w3.org/2000/svg" width="18" height="18" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round" class="tabler-icon tabler-icon-infinity "><path d="M9.828 9.172a4 4 0 1 0 0 5.656a10 10 0 0 0 2.172 -2.828a10 10 0 0 1 2.172 -2.828a4 4 0 1 1 0 5.656a10 10 0 0 1 -2.172 -2.828a10 10 0 0 0 -2.172 -2.828"></path></svg></span><span class="mantine-List-itemLabel">Lifetime access</span></div></li><li style="line-height:var(--mantine-line-height-xl)" class="m_abb6bec2 mantine-List-item" data-with-icon="true" data-centered="true"><div class="m_75cd9f71 mantine-List-itemWrapper"><span class="m_60f83e5b mantine-List-itemIcon"><svg xmlns="http://www.w3.org/2000/svg" width="18" height="18" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round" class="tabler-icon tabler-icon-clock "><path d="M3 12a9 9 0 1 0 18 0a9 9 0 0 0 -18 0"></path><path d="M12 7v5l3 3"></path></svg></span><span class="mantine-List-itemLabel">Learn at your own pace</span></div></li></ul><div style="--stack-gap:var(--mantine-spacing-xs);--stack-align:stretch;--stack-justify:flex-start" class="m_6d731127 mantine-Stack-root"><a style="--button-height:var(--button-height-md);--button-padding-x:var(--button-padding-x-md);--button-fz:var(--mantine-font-size-md);--button-color:var(--mantine-color-white);text-decoration:none" class="mantine-focus-auto m_849cf0da mantine-focus-auto mantine-active m_77c9d27d mantine-Button-root m_87cf2631 mantine-UnstyledButton-root m_b6d8b162 mantine-Text-root mantine-Anchor-root" data-size="md" data-underline="hover" href="https://hexlet.io/subscription/new"><span class="m_80f1301b mantine-Button-inner"><span class="m_811560b9 mantine-Button-label">Subscribe</span></span></a><p style="color:var(--mantine-color-dimmed);font-size:var(--mantine-font-size-sm);text-align:center" class="mantine-focus-auto m_b6d8b162 mantine-Text-root">Access this and all courses with a subscription</p></div></div></div></div></div></div></div></div>
</main>
<footer class="bg-dark fw-light text-light px-3 py-5">
<div class="row small">
<div class="col-12 col-sm-6 col-md-3">
<div class="h5 mb-3">About Hexlet</div>
<ul class="list-unstyled">
<li>
<a class="nav-link link-light py-1 ps-0" href="/pages/about">About us</a>
</li>
<li>
<span class="nav-link link-light py-1 ps-0 external-link" data-href="https://help.hexlet.io/category/4316" data-target="_blank" role="button">Help</span>
</li>
<li>
<a class="nav-link link-light py-1 ps-0" target="_blank" rel="noopener noreferrer" href="/map">Site Map</a>
</li>
</ul>
</div>
<div class="col-12 col-sm-6 col-md-3">
<div class="h5 fw-normal mb-3">Learn</div>
<ul class="list-unstyled">
<li>
<a class="nav-link link-light py-1 ps-0" href="/courses_backend-development">Backend
</a></li>
<li>
<a class="nav-link link-light py-1 ps-0" href="/courses_devops">DevOps
</a></li>
<li>
<a class="nav-link link-light py-1 ps-0" href="/courses_frontend-development">Frontend
</a></li>
<li>
<a class="nav-link link-light py-1 ps-0" href="/courses_python">Python
</a></li>
<li>
<a class="nav-link link-light py-1 ps-0" href="/courses_testing">Testing
</a></li>
</ul>
</div>
<div class="col-12 col-sm-6 col-md-3">
<div class="h5"><span class="translation_missing" title="translation missing: en.layouts.footer_content.popular_courses_for_beginners">Popular Courses For Beginners</span></div>
<ul class="list-unstyled">
<li>
<a class="nav-link link-light py-1 ps-0" href="/programs/frontend">Frontend Developer</a>
</li>
</ul>
</div>
<div class="col-12 col-sm-6 col-md-3">
<div class="h5"><span class="translation_missing" title="translation missing: en.layouts.footer_content.popular_courses_for_advanced">Popular Courses For Advanced</span></div>
<ul class="list-unstyled">
<li>
<a class="nav-link link-light py-1 ps-0" href="/programs/web-development-free">Fundamentals of Web Development</a>
</li>
<li>
<a class="nav-link link-light py-1 ps-0" href="/programs/js-react-development">React</a>
</li>
<li>
<a class="nav-link link-light py-1 ps-0" href="/programs/css-animation">CSS Animation</a>
</li>
<li>
<a class="nav-link link-light py-1 ps-0" href="/programs/http-api">HTTP API</a>
</li>
<li>
<a class="nav-link link-light py-1 ps-0" href="/programs/layout-designer-positioning">Position CSS</a>
</li>
<li>
<a class="nav-link link-light py-1 ps-0" href="/programs/cli-basics">Command line basics</a>
</li>
<li>
<a class="nav-link link-light py-1 ps-0" href="/programs/git-basics-free">Git fundamentals</a>
</li>
</ul>
</div>
</div>
<hr>
<div class="row">
<div class="col-12 col-sm-4 col-md-2">
<div class="fs-4">
<ul class="list-unstyled d-flex">
<li class="me-3">
<a aria-label="Facebook" target="_blank" class="link-light" rel="noopener noreferrer nofollow" href="https://www.facebook.com/hexlethq"><span class="bi bi-facebook"></span>
</a></li>
<li class="me-3">
<a aria-label="Instagram" target="_blank" class="link-light" rel="noopener noreferrer nofollow" href="https://www.instagram.com/hello_hexlet/"><span class="bi bi-instagram"></span>
</a></li>
<li>
<a aria-label="Twitter" target="_blank" class="link-light" rel="noopener noreferrer nofollow" href="https://twitter.com/Hexlet_IO"><span class="bi bi-twitter-x"></span>
</a></li>
</ul>
</div>
<div class="mb-2 d-flex flex-column">
<a class="link-light text-decoration-none" rel="nofollow" href="mailto:support@hexlet.io">support@hexlet.io</a>
<a class="link-light text-decoration-none py-2" target="_blank" href="https://t.me/hexlet_help_bot">t.me/hexlet_help_bot</a>
</div>
<ul class="list-unstyled d-flex">
<li class="me-3">
<span class="link-light text-decoration-none opacity-50 x-font-size-18 opacity-100 external-link" rel="nofollow" data-href="https://hexlet.io/locale/switch?new_locale=en" data-target="_self" role="button"><span class="my-auto">EN</span>
</span></li>
<li class="me-3">
<span class="link-light text-decoration-none opacity-50 x-font-size-18 external-link" rel="nofollow" data-href="https://ru.hexlet.io/locale/switch?new_locale=ru" data-target="_self" role="button"><span class="my-auto">RU</span>
</span></li>
<li class="me-3">
<span class="link-light text-decoration-none opacity-50 x-font-size-18 external-link" rel="nofollow" data-href="https://kz.hexlet.io/locale/switch?new_locale=kz" data-target="_self" role="button"><span class="my-auto">KZ</span>
</span></li>
</ul>
</div>
<div class="col-12 col-sm-4 col-md-3">
<ul class="list-unstyled fs-4">
<li class="mb-3">
<a class="link-light text-decoration-none" href="tel:%2B7%20717%20272%2076%2070">+7 717 272 76 70</a>
<span class="d-block opacity-50 small">free call</span>
</li>
</ul>
</div>
<div class="col-12 col-sm-4 col-md-3">
<ul class="list-unstyled small">
<li>
<a class="nav-link link-light py-1 ps-0" href="/pages/legal">Legal</a>
</li>
<li>
<a class="nav-link link-light py-1 ps-0" href="/pages/offer"><span class="translation_missing" title="translation missing: en.layouts.footer_content.offer">Offer</span></a>
</li>
<li>
<a class="nav-link link-light py-1 ps-0" href="/pages/contacts"><span class="translation_missing" title="translation missing: en.layouts.footer_content.contacts">Contacts</span></a>
</li>
</ul>
</div>
<div class="col-12 col-sm-12 col-md-4 small">
<div class="mb-2">
<div>TOO "Hexlet"</div>
<div>The Republic of Kazakhstan, Almaty</div>
<div>Auezova St., 14A</div>
<div>BIN 230340043714
</div>
</div>
</div>
</div>
</footer>
<div id="root-assistant-offcanvas"></div>
<script src="/vite/assets/assistant-CIOaBlj-.js" crossorigin="anonymous" type="module"></script><link rel="modulepreload" href="/vite/assets/chunk-DsPFFUou.js" as="script" crossorigin="anonymous">
<link rel="modulepreload" href="/vite/assets/init-0bhwJkNI.js" as="script" crossorigin="anonymous">
<link rel="modulepreload" href="/vite/assets/ErrorFallbackBlock-V3hfk_CP.js" as="script" crossorigin="anonymous">
<link rel="modulepreload" href="/vite/assets/MarkdownBlock-DejNWqwz.js" as="script" crossorigin="anonymous">
<link rel="modulepreload" href="/vite/assets/gon-B-jV56Ol.js" as="script" crossorigin="anonymous">
<link rel="modulepreload" href="/vite/assets/mantine-DOJkeu70.js" as="script" crossorigin="anonymous">
<link rel="modulepreload" href="/vite/assets/shiki-DZwEN4Zo.js" as="script" crossorigin="anonymous">
<link rel="modulepreload" href="/vite/assets/utils-ClTF9s_T.js" as="script" crossorigin="anonymous">
<link rel="modulepreload" href="/vite/assets/routes-mvvEXZQ8.js" as="script" crossorigin="anonymous">
<link rel="modulepreload" href="/vite/assets/lib-CJocDKTE.js" as="script" crossorigin="anonymous">
<link rel="modulepreload" href="/vite/assets/Box-DH3_MBnL.js" as="script" crossorigin="anonymous">
<link rel="modulepreload" href="/vite/assets/notifications.store-Cj65YiRw.js" as="script" crossorigin="anonymous">
<link rel="modulepreload" href="/vite/assets/useIsomorphicEffect-Csl7vw8x.js" as="script" crossorigin="anonymous">
<link rel="modulepreload" href="/vite/assets/lib-DeAQqnBE.js" as="script" crossorigin="anonymous">
<link rel="modulepreload" href="/vite/assets/axios-CN66HKVH.js" as="script" crossorigin="anonymous">
<link rel="modulepreload" href="/vite/assets/classnames-DQgTDFJJ.js" as="script" crossorigin="anonymous">
<link rel="modulepreload" href="/vite/assets/dayjs.min-Bfba02I7.js" as="script" crossorigin="anonymous">
<link rel="modulepreload" href="/vite/assets/debounce-BcxwEZ7X.js" as="script" crossorigin="anonymous">
<link rel="modulepreload" href="/vite/assets/prop-types-DGBR76ns.js" as="script" crossorigin="anonymous">
<link rel="modulepreload" href="/vite/assets/client-CYyKzrjQ.js" as="script" crossorigin="anonymous">
<link rel="modulepreload" href="/vite/assets/react-dom-SJZekO2j.js" as="script" crossorigin="anonymous">
<link rel="modulepreload" href="/vite/assets/useTranslation-bo78L81P.js" as="script" crossorigin="anonymous">
<link rel="modulepreload" href="/vite/assets/compiler-runtime-BhqaZ6vG.js" as="script" crossorigin="anonymous">
<link rel="modulepreload" href="/vite/assets/jsx-runtime-DlXMvSuQ.js" as="script" crossorigin="anonymous">
<link rel="modulepreload" href="/vite/assets/react-CFtMU8gd.js" as="script" crossorigin="anonymous">
<script defer src="https://static.cloudflareinsights.com/beacon.min.js/vcd15cbe7772f49c399c6a5babf22c1241717689176015" integrity="sha512-ZpsOmlRQV6y907TI0dKBHq9Md29nnaEIPlkf84rnaERnq6zvWvPUqr2ft8M1aS28oN72PdrCzSjY4U6VaAw1EQ==" data-cf-beacon='{"version":"2024.11.0","token":"d11015b65d11429ea6b4a2ef37dd7e0b","server_timing":{"name":{"cfCacheStatus":true,"cfEdge":true,"cfExtPri":true,"cfL4":true,"cfOrigin":true,"cfSpeedBrain":true},"location_startswith":null}}' crossorigin="anonymous"></script>
</body>
</html>