Code-Memo

API Design Best Practices

Consistency in naming and structure

1. One style for plurals, casing, dates, and error envelopes across all services.
2. Reuse the same patterns for pagination, filtering, and sorting query names.
3. Internal microservices should still feel like one product to client teams.

Avoiding breaking changes

1. Prefer adding optional fields and new endpoints over renaming or removing.
2. If you must break, ship parallel routes or versions and a sunset plan.
3. Track usage metrics to see when old versions are safe to retire.

Keeping APIs simple

1. Fewer concepts mean faster adoption; resist generic super-endpoints that do everything.
2. Prefer clear defaults over forcing clients to send many flags.
3. Document happy path first; advanced options second.

Separation of concerns

1. Gateways handle cross-cutting concerns (authn, rate limits, TLS); services own domain rules.
2. Avoid leaking storage schema directly; expose stable DTOs.
3. Background work belongs in jobs/events, not hidden inside synchronous GETs.

Versioning strategy planning

1. Decide URI vs header versioning org-wide and stick to it per public surface.
2. Define what counts as major vs minor change for your consumers.
3. Automate contract diff in CI for every release candidate.