🗺️ React.js Interview Preparation Roadmap
Phase 1: Core Foundations (Week 1)
Revisit and master fundamentals — they’re always tested.
Topics:
- JavaScript (ES6+):
let/const, arrow functions, destructuring, spread/rest, template literals- Async JS: promises, async/await, fetch, error handling
- Closures, scopes, prototypes,
this, event loop, hoisting
- Array & object methods (
map, filter, reduce, etc.)
- HTML5 & CSS3:
- Semantic HTML, accessibility (a11y)
- Flexbox, Grid, animations, media queries
- CSS architecture: BEM, utility-first (Tailwind CSS)
Practice:
- Rebuild small components (Navbar, Cards, Modals) using only HTML/CSS/JS
- Platform: Frontend Mentor, CodeSandbox
Phase 2: React.js Deep Dive (Week 2)
Get very comfortable with core and advanced React patterns.
Topics:
- Functional components, Hooks (
useState, useEffect, useMemo, useCallback, useRef)
- Context API and custom hooks
- Component lifecycle (before & after hooks)
- React Router v6
- Conditional rendering and list rendering
- Error boundaries and Suspense
- Controlled vs uncontrolled components
- Lazy loading & code splitting
Projects/Practice:
- Build a Dashboard or Task Tracker app with CRUD
- Use React Router, Context API, and lazy loading
Phase 3: State Management & Architecture (Week 3)
Show your ability to design scalable front-end systems.
Topics:
- Redux Toolkit: slices, store, middleware, async thunks
- Zustand / Recoil: when to prefer them over Redux
- Data fetching: React Query, SWR
- Architecture:
- Folder structure and modular components
- Component-driven development (Storybook)
- Micro frontends basics (Module Federation)
Projects/Practice:
- Rebuild your app using Redux Toolkit and React Query
- Create reusable UI components (buttons, dropdowns, modals)
Phase 4: Performance, Testing, & Integration (Week 4)
This phase makes you stand out as a senior engineer.
Topics:
- Performance Optimization:
React.memo, useMemo, useCallback- Virtualization (
react-window, react-virtualized)
- Bundle optimization (Webpack, Vite)
- Lazy loading and tree-shaking
- Testing:
- Jest basics (mocking, snapshot testing)
- React Testing Library: unit & integration tests
- Cypress: end-to-end tests
- Integration:
- REST API + GraphQL (Apollo Client basics)
- Error handling and toast notifications
- Secure API communication (tokens, headers)
Practice:
- Add test coverage and API integration to your project
- Measure performance with React DevTools & Lighthouse
Phase 5: Advanced Topics & DevOps (Week 5–6)
Prepares you for system design and leadership-oriented questions.
Topics:
- Next.js: SSR, SSG, API routes, middleware
- Node.js + Express (Basics): simple backend for APIs
- CI/CD: GitHub Actions or GitLab CI basics
- Cloud & Deployment:
- Deploy on Vercel, AWS Amplify, or Netlify
- Environment variables, secrets, and scaling
- Docker (Optional): containerize your app
- Agile & Team Practices:
- Code reviews, version control, branching strategies
- Mentoring juniors and conducting code reviews
🧩 Bonus Preparation
- Interview-Focused Practice:
- System design for front-end (component hierarchy, data flow)
- Behavioral questions (mentoring, decision-making, trade-offs)
- Past project deep dive: explain why you used a specific stack.
- Mock Resources:
- Frontend Interview Handbook
- React Patterns
- System Design for Frontend
🕒 Suggested Weekly Plan (Example)
| Week |
Focus |
Output |
| 1 |
JS + HTML + CSS |
Mini component library |
| 2 |
React Core |
Task Tracker App |
| 3 |
Redux + Architecture |
Scalable Dashboard |
| 4 |
Performance + Testing |
Add Jest/Cypress |
| 5 |
Next.js + CI/CD |
Deployed full-stack project |