During January 2025, Dan Danilov focused on refactoring file system operations in the tact-lang/tact repository. He replaced the external mkdirp dependency with the native Node.js fs.mkdirSync method using the recursive option, streamlining dependency management and simplifying the codebase. Working in TypeScript, Dan ensured that the refactor preserved existing behavior while improving cross-platform compatibility and reducing maintenance overhead. The changes were validated through targeted code reviews and testing, resulting in a more idiomatic and reliable file system implementation. This foundational work did not introduce user-facing features but established a cleaner, more maintainable platform for future development efforts.