Contracts beat tribal knowledge
Version your APIs intentionally. Document error shapes. Treat breaking changes as a migration project, not a surprise.
Backpressure is a feature
Queues, rate limits, and timeouts are how you protect databases and humans from each other. If your system cannot say “slow down,” it will fail loudly later.
Observability is not optional
Trace requests end-to-end. Put business identifiers in logs—carefully. Alerts should point to remediations, not panic.
What we ship differently now
Stricter defaults on pagination, idempotency keys for writes, and contract tests in CI. Small disciplines compound when traffic arrives.