Developed concurrency enhancements for the oxcaml/oxcaml repository by implementing a reader-writer lock and expanding the capsule API to support shared data access. This work introduced new APIs, map_shared and extract_shared, enabling safe and scalable concurrent manipulation of capsule data in OCaml. The approach focused on concurrency control and system programming, with comprehensive tests added to ensure correctness and thread-safety. By laying the foundation for multi-threaded usage, these changes improved the safety and throughput of concurrent workloads. The implementation leveraged both OCaml and C, emphasizing robust API design and careful handling of shared resources in a concurrent environment.