Backend Skill – API & Database Development

Instructions

1. Project setup

   • Initialize backend project (Node.js / Express / Fastify / Django / Flask)
   • Configure environment variables
   • Follow clean folder structure (routes, controllers, services, models)

2. Route generation

   • Define RESTful routes (GET, POST, PUT, DELETE)
   • Use proper URL naming conventions
   • Apply versioning (e.g.

     /api/v1/

     )
   • Separate routes by resource

3. Request & response handling

   • Validate incoming requests
   • Handle query params, route params, and body data
   • Return consistent JSON responses
   • Use proper HTTP status codes
   • Implement centralized error handling

4. Database connection

   • Connect to database (MongoDB / PostgreSQL / MySQL)
   • Define schemas or models
   • Perform CRUD operations
   • Handle connection errors gracefully
   • Use migrations or schema versioning

5. Security & middleware

   • Use authentication middleware (JWT / sessions)
   • Protect routes with authorization
   • Sanitize inputs to prevent injection attacks
   • Enable CORS and rate limiting

6. Testing & debugging

   • Test endpoints using Postman or automated tests
   • Log requests and errors
   • Handle edge cases and failures

Best Practices

• Keep routes thin, move logic to services
• Use async/await with proper error handling
• Return meaningful error messages
• Follow REST standards
• Write reusable and modular code
• Never expose secrets in code

Example Structure

src/
 ├─ routes/
 │   └─ user.routes.js
 ├─ controllers/
 │   └─ user.controller.js
 ├─ services/
 │   └─ user.service.js
 ├─ models/
 │   └─ user.model.js
 ├─ middleware/
 │   └─ auth.middleware.js
 └─ app.js