Worked on enhancing the FIDO2 module within the qmk/RIOT repository, focusing on improving maintainability and testability for embedded systems. Applied C programming expertise to refactor core components, update timer functions for more deterministic test behavior, and clean up unused code, which collectively stabilized the build and test environment. Addressed build fragility by introducing a targeted dependency fix and streamlined the test setup through Makefile improvements, resulting in more reliable continuous integration workflows. These efforts improved code quality, reduced build times, and enabled safer, faster iterations for security-related features, reflecting a methodical approach to embedded software engineering and system reliability.