In April 2025, 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 reduced unnecessary code noise, making the codebase easier to navigate and maintain. By eliminating obsolete debug statements, Cheng lowered cognitive load for future debugging and code reviews, supporting ongoing maintainability efforts. The work leveraged skills in code cleanup and debugging, aligning with broader repository quality initiatives. While no major bugs were addressed during this period, the cleanup laid a foundation for smoother future refactors and contributed to long-term code stability.