Develow
← Problem sets
Official6 problems · ~4.5h total

Zero to Hero: React

Go from React fundamentals to interview-ready. A difficulty-ramped set of multi-concept React problems — controlled components, derived state, effects and cleanup, memoization and re-render control, controlled vs uncontrolled inputs, and keys/reconciliation — each graded by black-box Playwright tests over the real DOM. Built to help you pass the React front-end interview.

0/6 solved0%

Warm-up — Fundamentals

Controlled Components — Sign-up Form

Debugging · 45 min · react-hooks

easy
Searchable, Filterable Product List

Debugging · 45 min · react-hooks, state-management

easy

Core — Hooks & Performance

Live Search with useEffect

Debugging · 45 min · react-hooks, async, state-management

medium
Stop the Re-renders — useMemo, useCallback, React.memo

Debugging · 45 min · react-hooks, performance-optimization

medium

Challenge — Advanced Patterns

Controlled vs Uncontrolled — Tame the Form + Focus

Debugging · 45 min · react-hooks, state management, focus management

hard
Keys & Reconciliation — No State Bleed on Reorder

Debugging · 45 min · react-hooks, state-management

hard
Zero to Hero: React