Nils Ollrogge enhanced the FIDO2 module in the qmk/RIOT repository, focusing on maintainability and testability within embedded systems. He refactored core components in C, introducing a new dependency and removing unused code to streamline the codebase. By updating timer functions, he improved deterministic behavior in tests, while targeted Makefile adjustments stabilized the build and test environment, supporting more reliable continuous integration. A small dependency fix further reduced build fragility and integration risks. Nils’s work improved code quality and accelerated safe development cycles for security-related features, demonstrating depth in C programming, embedded systems, and build automation with Makefile.