Cheng Chen focused on improving code hygiene in the libsdl-org/aom repository by systematically removing commented-out printf debugging statements from C and C++ files. This targeted code cleanup aimed to reduce unnecessary code noise, making the codebase easier to navigate and maintain for future development. By leveraging skills in code cleanup and debugging, Cheng streamlined the repository, lowering cognitive load for developers during code reviews and debugging sessions. Although no major bugs were addressed during this period, the work laid a foundation for smoother future refactors and long-term stability, reflecting a thoughtful approach to maintainability and collaborative engineering practices.