Engineering18/08/20266 min read
Designing Reliable API Boundaries
A few principles for keeping API contracts predictable as a product grows.
Reliable APIs start with explicit contracts: inputs, outputs, failure modes, and ownership should be clear before implementation begins.
Keeping domain validation close to the boundary prevents invalid state from leaking into the rest of the system.
Small, observable interfaces are easier to test, evolve, and operate than broad endpoints that hide multiple responsibilities. My Portfolio