Building Scalable REST APIs with Node.js

# Building Scalable REST APIs

Learn how to build production-ready REST APIs that can handle millions of requests.

## Project Structure

Organize your API for scalability:

```
src/
├── controllers/
├── models/
├── routes/
├── middleware/
├── services/
└── utils/
```

## Error Handling

Centralized error handling:

```typescript
class ApiError extends Error {
statusCode: number;

constructor(message: string, statusCode: number) {
super(message);
this.statusCode = statusCode;
}
}

app.use((err: Error, req: Request, res: Response, next: NextFunction) => {
if (err instanceof ApiError) {
return res.status(err.statusCode).json({
error: err.message,
});
}

return res.status(500).json({
error: 'Internal server error',
});
});
```

## Rate Limiting

Protect your API from abuse:

```typescript
import rateLimit from 'express-rate-limit';

const limiter = rateLimit({
windowMs: 15 * 60 * 1000, // 15 minutes
max: 100, // Limit each IP to 100 requests per windowMs
});

app.use('/api/', limiter);
```