A good API is not just one that works, but one that can be understood and developed by the team in the long term. I have a principle: the API contract is more important than the implementation.
I always start with an OpenAPI specification before writing a single line of code. This forces me to think about edge cases, error responses, and versioning strategy from the beginning.
API Design Principles
- Consistency: Use consistent resource naming conventions and plural forms (users, orders, products)
- Filtering and pagination: Always provide standard filter, sort, and pagination mechanisms
- Error handling: Error responses must be informative with a consistent JSON format
- Rate limiting: Protect endpoints from abuse with sensible throttling
Tools like Postman collections and API documentation auto-generated from OpenAPI are very valuable investments.