During May 2025, Yuchen Liu developed a personalized course listing feature for the ucsb-cs156/proj-frontiers repository, enabling users to view all courses in which they are enrolled. Leveraging Java, Spring Boot, and JPA, Yuchen implemented a backend endpoint within the CoursesController and ensured robust test coverage using JUnit. The work included refactoring user email retrieval logic to streamline code and reduce potential errors, enhancing maintainability and reliability. No major bugs were reported during this period, reflecting careful engineering and attention to detail. The feature addressed user value directly and improved the backend’s clarity and testability for future development.