Building resilient APIs with clear boundaries

Designing for long-term maintainability

The biggest win in API design is not just shipping quickly, but keeping the contract honest enough that future changes do not become expensive rewrites.

When I build backend services, I think about the explicit boundary between transport, business logic, and persistence. That separation makes it easier to evolve a system without coupling every layer to the same failure mode.

A simple rule of thumb: if a change requires touching multiple layers for a single feature, the boundary is probably too vague.