Senior frontendTop product companies

A2Z Frontend

Master the path. Own the panel.

216 topics curated for top product company frontend loops—structured module guides with interview questions and panel-ready solutions for senior panels.

Free · 150 topics · Module-wise guides & solutions

Built for senior loops

Frontend interviews at top companies

One structured path from JavaScript fundamentals to system design—aligned with how Google, Meta, Amazon, and similar panels run senior frontend loops.

  • Senior frontend engineer
  • Staff / principal track
  • React & TypeScript depth
  • Top product company loops
  • Machine coding rounds
  • Frontend system design

How the track is organised

Three phases, ten modules

Follow the recommended order—each module builds on the last, aligned with how top product companies structure senior frontend interviews.

Modules 1–4

Core stack

Language, types, and the frameworks every panel assumes you know deeply

  • JavaScript fundamentals, async & design patterns
  • TypeScript generics, unions & strict typing
  • React hooks, performance & state management
  • Next.js rendering modes, caching & Server Actions
Modules 5–7

Platform & craft

Browser internals, security, and how strong teams ship production UI

  • Rendering pipeline, Web Vitals & optimisation
  • XSS, CSRF, auth flows & OAuth PKCE
  • Bundlers, monorepos & internal web architecture
Modules 8–9

The interview room

Live coding and frontend system design under time pressure

  • 45-minute UI builds—tabs, lists, autocomplete
  • Frontend system design—feeds, RBAC, wizards, real-time UI

Full curriculum

Every module, in prep order

Each row opens a module guide—topics grouped by category with interview questions and solutions.

#ModuleTopics
01JavaScript

The floor for every round—closures, event loop, async, utilities, and patterns panels still drill.

Event loop & closuresPolyfills & patterns
29Open
02TypeScript

Types you defend in a staff loop—generics, strict mode, unions, and production API shapes.

Generics & utility typesConditional & mapped types
10Open
03React

Hooks, Fiber, render perf, and state trade-offs—beyond todo-app answers.

Reconciliation & hooksZustand vs React Query
29Open
04Next.js

SSR modes, App Router, streaming, caching—ship React and explain why.

SSR / SSG / ISRServer Actions & cache
7Open
05Browser & Performance

URL → pixel, V8, networking, Core Web Vitals—senior “what happens when…” rounds.

Rendering pipelineLCP, INP, CLS
12Open
06Security

XSS, CSRF, token storage, OAuth PKCE—gaps that fail otherwise strong candidates.

XSS & CSRFAuth in SPAs
6Open
07Build Tools & Architecture

Bundlers, ESM, monorepos, feature flags—how top teams ship and scale frontends.

Vite vs WebpackPlatform & observability
13Open
08Machine Coding

45-minute UI builds—tabs, virtual lists, autocomplete—clean code under clock pressure.

Accessible componentsState & edge cases
100Open
09Frontend System Design

The final 10 FSD patterns—e-commerce, chat, docs, feed, video, Jira, drive, dashboard, design system, micro-frontends.

Real interviewer promptsFull architecture walkthroughs
10Open

Based on the senior frontend prep sheet (PDF)· 216 guided topics

Every topic page includes

  • The exact interview question from the sheet
  • Structured guide with concept breakdown
  • Panel-ready solution you can defend live
  • Follow-ups interviewers ask next

Pair guides with live practice

After a module clicks, pressure-test in the machine coding editor—same timed UI builds top companies run.

Machine coding practice

JavaScript and React challenges in the browser—write code, run tests, and track progress on your profile.

  • Interview-style UI problems with starter templates
  • Automated tests in the live editor
  • Profile dashboard for solved challenges