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Overview

HTML

All HTML

What is semantic HTML?

When should you use a button instead of a link?

How do forms associate labels with inputs?

What is the document outline?

What are custom data attributes?

How do HTML templates work?

What is the purpose of the meta viewport tag?

How do you use responsive images?

What is the difference between defer and async scripts?

How do you structure an accessible table?

CSS

All CSS

How does CSS specificity work?

What is the CSS box model?

When should you use Flexbox versus Grid?

How do stacking contexts work?

What is the difference between relative, absolute, fixed, and sticky positioning?

How do container queries work?

What are CSS custom properties?

How do you prevent layout shift with CSS?

What is the cascade layer feature?

How do you build responsive layouts without device-specific breakpoints?

Next.js

All Next.js

What is Next.js?

What is the difference between the App Router and Pages Router?

What are React Server Components in Next.js?

When do you use a Server Component versus a Client Component?

How does Next.js data fetching and caching work?

What are route handlers?

How do dynamic routes work in Next.js?

How do you handle loading and error states in the App Router?

What is static generation versus server-side rendering?

How do you optimize images and fonts in Next.js?

Redux

All Redux

What are the core Redux principles?

What are actions, reducers, and the store?

Why must Redux reducers be pure?

What is Redux Toolkit?

What is a selector?

How do you handle async logic with Redux?

What is middleware?

What is normalized state?

How do you avoid unnecessary Redux re-renders?

When is Redux not a good fit?

RxJS

All RxJS

What is an Observable?

How does an Observable differ from a Promise?

What is a Subject?

When do you use BehaviorSubject?

How do switchMap, mergeMap, concatMap, and exhaustMap differ?

What do debounceTime and distinctUntilChanged do?

How do you unsubscribe safely?

How do you handle errors in an RxJS stream?

What is a cold versus hot Observable?

How do you test an Observable pipeline?

Web Performance

All Web Performance

What are Core Web Vitals?

How do you reduce Largest Contentful Paint?

How do you avoid Cumulative Layout Shift?

How do you improve Interaction to Next Paint?

What is the critical rendering path?

When should you lazy load code or images?

How do you measure web performance?

What causes long tasks on the main thread?

How do you use a performance budget?

How do you optimize third-party scripts?

Web Security

All Web Security

What is the same-origin policy?

What is CORS?

What is cross-site scripting?

How do you prevent XSS?

What is CSRF and how can it be mitigated?

Why is Content Security Policy important?

How should sensitive tokens be stored in a browser?

What cookie attributes improve security?

How do you safely render untrusted content?

How do you protect a frontend supply chain?

Accessibility

All Accessibility

What does web accessibility mean?

How do you use semantic HTML for accessibility?

When should you use ARIA?

How do you make a custom control keyboard accessible?

How do you manage focus in a modal dialog?

What is accessible name and description?

How do you test a page with a screen reader?

How do you meet color contrast requirements?

How do you support reduced motion preferences?

What is an accessible error message for a form field?

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