Michael Carlberg enhanced the Sundsvallskommun/api-service-messaging repository by improving integration test coverage and stability for the messaging service. He introduced bodyPatterns to integration tests using Java, enabling validation of request payloads and more comprehensive end-to-end testing. After a rebase, Michael addressed a failing integration test, restoring the test suite’s green status and ensuring continuous integration reliability. His backend development and testing efforts reduced regression risk and accelerated feedback cycles. By clearly linking changes to specific commits, he improved traceability for future audits and reviews. The work demonstrated depth in integration testing and backend development within a Java-based environment.