Worked on the CAUSW_backend repository to enhance backend reliability and maintainability through targeted feature development. Focused on improving error handling by introducing a NotFoundException class, enabling precise reporting for missing resources and establishing clearer error contracts. Refactored the Password Finding API to streamline its interface, removing unused response data and trimming input fields to address whitespace issues, while switching the return type to void for cleaner API design. Emphasized API refactoring, input sanitization, and exception handling using Java and the Spring framework, laying a foundation for more robust backend code and consistent error management practices in future development cycles.