Your API is a product. Treat breaking changes like product incidents: version explicitly, document deprecations with dates, and offer migration notes.
Consistent error messages save more support hours than any dashboard.
Use predictable pagination—cursor for large streams, offset only when datasets are bounded. Always return stable sort keys so clients do not see duplicates when data shifts.
Idempotency keys on writes prevent duplicate orders and duplicate payouts. This is especially important for marketplaces and billing.
Log correlation IDs end-to-end so when a partner opens a ticket you can trace the request without guessing.
