Worked on the DEFRA/water-abstraction-system repository, focusing on enhancing the reliability of the FetchCurrentReturnCycleService. Addressed a critical bug by aligning test logic with the service’s behavior for both summer and non-summer periods, ensuring accurate determination of the current return cycle. Refactored the test suite using JavaScript and Node.js, simplifying setup and removing redundant tests to streamline regression testing and reduce maintenance overhead. Emphasized robust testing practices to improve regression coverage, which helps prevent future issues. These improvements increased the reliability of return cycle calculations, reduced risk for downstream processes, and contributed to safer, more confident deployments for the system.