The API-First Manifesto
By defining REST schemas using Swagger/OpenAPI specifications before writing backend code, developers ensure compatibility, ease of integration, and reliable validation rules. The API becomes the contract between the frontend, mobile, and third-party developers.
Versioning and Backward Compatibility
APIs evolve. Changing a payload structure can crash mobile apps that users haven't updated yet. We implement URL-level versioning (e.g., `/api/v1/orders` vs `/api/v2/orders`) to route legacy traffic to older controllers, while new clients use the optimized endpoints.
- Never remove fields from an active API version, only append them.
- Use API Gateway (like Kong or AWS API Gateway) to manage traffic and deprecation logs.
- Implement strict input validation using Zod or Joi to reject malformed requests.
Rate Limiting and Throttling
To protect the database from DDoS attacks or aggressive scraping, we implement Redis-backed token bucket rate limiters. Free tier users might get 60 requests/minute, while Enterprise users get 1000 requests/minute, defined in their API key metadata.