Api Contract Testing

Helps you set up contract testing between services so you don't break APIs when deploying changes. Instead of running full integration tests, you validate that your service honors the contract consumers expect. Covers Pact for consumer-driven contracts, OpenAPI schema validation, and integration with Pact Broker for sharing contracts across teams. Most valuable in microservices architectures where you need to catch breaking changes before they hit production. The Pact implementation is solid and the reference guides cover both TypeScript and Java. Worth noting that contract tests complement integration tests rather than replace them, since they focus on API shape and format rather than business logic.