api-and-interface-design

Contract-first API design defines the interface and public surface before implementation to reduce misuse and coupling. Use it when designing REST or GraphQL endpoints, module boundaries, or public interfaces across teams to establish clear contracts.

Design REST and GraphQL APIs for backward compatibility by preferring additive changes over breaking modifications. This approach maintains stable contracts, standardizes resource design and pagination, and minimizes disruptions across services.

Standardize API error responses by aligning them to a single, predictable format across all endpoints. This consistent error semantics approach reduces misuse and ensures predictable behavior across REST and GraphQL surfaces.

Validate API inputs at the boundary to prevent internal leakage by enforcing contract-first rules. This boundary validation ensures correctness, stops invalid data from reaching internal services, and maintains interface stability.

Yes, you can use this approach for defining module boundaries across teams. It establishes clear public interfaces and stable contracts before implementation, reducing coupling and preventing misuse between different services and components.

The best way to version API contracts without breaking changes is to prefer additive changes. This extension method maintains forward compatibility, stabilizes the public surface, and minimizes disruptions across REST or GraphQL endpoints.