Contract Testing Essentials (Pact)

Store consumer contracts beside the integration specs that generate them; version contracts semantically and publish on every CI run.
Require provider verification before merge; failed verification blocks release and surfaces breaking changes immediately.
Capture fallback behaviour inside interactions (timeouts, retries, error payloads) so resilience guarantees remain explicit.
Automate broker housekeeping: tag releases, archive superseded contracts, and expire unused pacts to reduce noise.
Pair contract suites with API smoke or component tests to validate data mapping and UI rendering in tandem.

Source: Pact consumer/provider sample repos, Murat contract testing blog.