Worked on the koreader/koreader repository to enhance file system reliability across devices by addressing issues with vFAT filename compatibility. Focused on a targeted bug fix that improved the handling of illegal filenames by replacing invalid characters with underscores and trimming trailing spaces and dots, ensuring successful file and directory creation on platforms like Kobo. Utilized Lua for implementing robust string manipulation and defensive file I/O practices, which reduced user-reported errors related to file handling. The work demonstrated attention to cross-device interoperability and code quality, contributing to greater stability and user satisfaction without introducing new features during the development period.