Worked on backend stability and usability improvements across open-source projects, focusing on error handling and file management. In the rclone/rclone repository, addressed a command-line interface crash by implementing defensive argument validation in Go, ensuring the CLI handled empty input gracefully and improving automation reliability. Later, contributed to huggingface/transformers by resolving a file permission issue in Python, replacing shutil.copy with shutil.copyfile to ensure saved Transformer models received correct, user-writable permissions. These targeted bug fixes enhanced user experience and reduced support overhead, demonstrating a methodical approach to backend development, command-line interface robustness, and cross-platform file handling in both Go and Python.