api-and-interface-design

To prevent breaking changes in a REST API, establish strict contract-first design patterns, apply boundary validation, and adhere to the One-Version Rule for all public-facing interfaces to minimize system coupling.

Hyrum's Law in interface design states that all observable API behaviors become implicit contracts. You must enforce strict boundary validation and contract-first schemas to manage this implicit consumer coupling safely.

Implement contract-first design for TypeScript module boundaries by defining interfaces and types before implementation, ensuring alignment and reducing coupling across distributed system components.

The best way to standardize API error responses is to enforce unified error semantics, ensuring predictable behavior for consumers across all module boundaries and public-facing interface contracts.

Contract-first design works for both REST endpoints and GraphQL schemas. It establishes stable interface patterns, applies boundary validation, and ensures consistent error handling across distributed systems.

Boundary validation at system edges is required to protect internal logic from untrusted external data. It implements robust input validation to prevent breaking changes and ensure consistent module behavior.