api-and-interface-design

Design a stable REST API by applying additive extension patterns, boundary validation, and predictable naming conventions to prevent accidental breaking changes. This ensures backward compatibility when evolving public interfaces and module boundaries.

Standardize error handling by defining consistent error shapes and validating inputs at system boundaries. This approach avoids ambiguous consumer behavior and ensures predictable API interactions across REST and GraphQL endpoints.

Implement contract-first API definitions by specifying typed inputs and outputs before writing code, making the interface the source of truth. This technique applies directly to designing REST endpoints, GraphQL schemas, and component props.

Yes, contract-first API design works for database-informed API shapes, module boundaries, and component prop contracts. It applies consistent error semantics, boundary validation, and pagination to any public interface being created or modified.

Use additive changes, pagination, discriminated unions, and branded IDs when evolving public interfaces to preserve backward compatibility and reduce coupling. These patterns ensure existing consumers continue functioning while the API grows.