Worked on the microsoft/documentdb repository to enhance performance and code quality by refactoring asynchronous closures in Rust. The approach focused on borrowing string values instead of cloning them, which reduced unnecessary memory allocations and clarified ownership semantics within async blocks. This change improved runtime efficiency and maintainability without altering the existing API or requiring additional tests, as all current tests continued to pass. The work demonstrated a strong understanding of asynchronous programming and performance optimization in Rust, delivering targeted improvements through a pull request-driven workflow while ensuring stability and preserving the original behavior of the codebase throughout the process.