Worked on enhancing the Dune cache for Windows in the ocaml/dune repository, focusing on backend development and file system management using OCaml. Delivered a feature that leverages hard links to reduce cache duplication and implemented logic to handle read-only destinations during file renames, improving cache reliability and performance. Addressed Windows-specific deduplication issues and stabilized related tests, which increased CI consistency and aligned behavior with Unix environments. Emphasized robust system programming practices by improving Windows IO handling and error propagation, ultimately reducing cache-related failures and supporting cross-platform parity. The work targeted faster builds and more efficient disk usage for developers.