Node JS Practical Examination Definations

 Got it 👍 Since you already know basics (CRUD, JWT, DB, Passport), let’s focus on advanced Node.js practical examples you can practice before your exam. These are real-world backend challenges companies love to test.

---

🔥 Advanced Practical Examples

1. Role-Based Access Control (RBAC)

• Task: Create a system with roles → admin, manager, user.

• Practice:

  • Only admin can delete users.

  • manager can view all users but not delete.

  • user can only view their own profile.

• Concepts: Middleware, JWT payload roles, route authorization.

---

2. Refresh Tokens & Logout

• Task: Implement access tokens + refresh tokens.

• Practice:

  • Login returns both tokens.

  • Access token expires in 15 min.

  • Refresh token stored in DB → can request new access token.

  • Logout = invalidate refresh token.

• Concepts: JWT lifecycle, token blacklisting, DB session management.

---

3. File Upload + Cloud Storage

• Task: Upload image → store in AWS S3 (or local folder for practice).

• Practice:

  • POST /upload → Upload profile picture.

  • Validate file type (only .jpg, .png).

  • Save file URL in DB.

• Concepts: multer, cloud SDKs, validation.

---

4. Pagination + Filtering + Search

• Task: Build /products API.

• Practice:

  • GET /products?page=2&limit=10&category=books&search=node

  • Return paginated results with filters.

• Concepts: Query params, Sequelize/Mongoose queries, API response structure.

---

5. Rate Limiting & Security

• Task: Protect API against abuse.

• Practice:

  • Allow max 100 requests per IP per 15 min.

  • Block IP if exceeded.

• Concepts: express-rate-limit, middleware, security headers.

---

6. Background Jobs / Queues

• Task: Send welcome email after user registers.

• Practice:

  • Push task into Redis queue.

  • Worker sends email after delay.

• Concepts: bull or agenda, job queues, async processing.

---

7. Socket.IO Real-time Chat

• Task: Create real-time chat API.

• Practice:

  • user1 sends → user2 receives instantly.

  • Store messages in DB.

  • Add “online/offline” status.

• Concepts: WebSockets, events, broadcasting.

---

8. API Gateway + Microservices

• Task: Split app into microservices.

• Practice:

  • Service 1: Users

  • Service 2: Products

  • API Gateway routes requests /users/* → User service, /products/* → Product service

• Concepts: Reverse proxy, scaling, service separation.

---

9. GraphQL API

• Task: Replace REST with GraphQL.

• Practice:

  • Query user details with nested posts.

  • Mutation to create/update user.

• Concepts: apollo-server, schema, resolvers.

---

10. Testing (Unit + Integration)

• Task: Write tests for login API.

• Practice:

  • Test success login → returns token.

  • Test wrong password → returns 400.

  • Test protected route → returns 401 without token.

• Concepts: jest / mocha, supertest, mocking DB.

---

🚀 Suggested Practice Path

1. ✅ Implement RBAC + JWT refresh tokens

2. ✅ Add file upload with S3/local

3. ✅ Create products API with pagination + filtering

4. ✅ Secure APIs with rate limiting & helmet

5. ✅ Build chat app with Socket.IO

6. ✅ Add queues for async jobs

7. ✅ Try GraphQL for bonus points

8. ✅ Write unit tests

---

👉 Would you like me to create a full advanced-level practice exam (like a real company might give, combining 3–4 of these challenges in a 3-hour task)?