Frontend Interview Preparation Guide

This guide will help you prepare for a frontend developer interview. We'll cover what interviewers ask, how to prepare, and which platform tools to use at each stage.


What a Frontend Interview Looks Like

A typical interview includes three stages:

  1. Theory — questions on HTML, CSS, JavaScript, TypeScript, frameworks, browser, networking and architecture
  2. Practice — writing code: JavaScript, React, TypeScript, promise and layout tasks
  3. Behavioral interview — experience, approach to work, team collaboration

Theory and practice can be prepared systematically. The platform has a roadmap that structures preparation and tracks your progress.


Step 1. Roadmap

Start with the preparation roadmap. It's split into three directions: theory, practice and knowledge check. Each topic links to specific materials on the platform. Progress is tracked automatically, and you can skip topics you already know.

The roadmap gives you the full picture of what you need to know and helps you avoid missing important topics.


Step 2. Theory

Study sections from the knowledge base in the order suggested by the roadmap, or choose topics yourself.

HTML and CSS

HTML & CSS — semantic markup, Flexbox, Grid, positioning, responsive design, accessibility.

Common questions: difference between inline and block, selector specificity, how z-index works, Flexbox vs Grid.

JavaScript

JavaScript — data types, closures, prototypes, event loop, promises, async/await, this, classes, modules.

This is the most extensive section. Interviewers often ask to explain the difference between let/const/var, how the event loop works, what a closure is, and how == differs from ===.

TypeScript

TypeScript — basic types, generics, utility types, conditional types, infer, function overloads.

TypeScript is asked about more and more often. It's worth understanding at least basic types, generics and Pick/Omit/Partial.

React

React — hooks, Virtual DOM, lifecycle, rendering, optimization, patterns.

Common questions: how useEffect works, difference between useMemo and useCallback, what Virtual DOM is and why it's needed, state management.

Next.js

Next.js — SSR, SSG, ISR, CSR, App Router, Server Components, routing, caching, Server Actions.

Next.js appears in job requirements more frequently. It's worth knowing the difference between rendering strategies and when to use each one.

Other Frameworks

  • Vue — reactivity, Composition API, directives
  • Angular — modules, DI, RxJS, Change Detection

General Knowledge

  • General Questions — HTTP, REST, browser, security (XSS, CSRF), performance, Core Web Vitals
  • Architecture — FSD, modular architecture, micro-frontends
  • Principles — SOLID, DRY, KISS, YAGNI
  • Patterns — Singleton, Observer, Factory, Decorator

Step 3. Practice

Theory without practice is quickly forgotten. The platform has problems from real interviews with a built-in IDE and instant checking.

Recommendation: solve problems out loud, talking through your thought process. In interviews, it's not just the solution that matters, but how you reason.


Step 4. Knowledge Check

530+ flashcards by category: JavaScript, React, TypeScript, HTML/CSS, Vue, Angular, Redux, general questions.

Format: question on one side, detailed answer on the other. Great for review before an interview or in your free time.


Step 5. Behavioral Interview

This stage can't be prepared with tasks, but you can think it through in advance.

Common questions:

  • Tell me about the most complex project you worked on
  • How do you resolve conflicts in a team
  • How do you estimate task timelines
  • Was there a time you made a mistake, and how did you fix it

Prepare 3-4 stories from your experience using the STAR format (Situation, Task, Action, Result). Specific examples with numbers and results sound more convincing than general statements.


Additional Resources

Documentation and References

Algorithm Practice

Books