Learn how to implement contract testing with Pact as a scalable solution to integration failures in distributed systems and microservices architectures. Discover the concept of executable agreements—living contracts between services that automatically validate API expectations in CI pipelines to catch mismatches before production deployment. Explore how contract testing integrates into modern development workflows, complements existing unit and integration testing strategies, and enhances team collaboration. Understand why traditional end-to-end tests are often too slow, flaky, and expensive for reliable safety nets, and see how Pact provides a practical alternative that enables teams to define and verify API expectations early, independently, and reliably across distributed system environments.