Worked on the prestodb/pbench repository to enhance the reliability of HTTP client header handling in concurrent environments. Addressed a concurrency bug by introducing mutex-based synchronization to protect header map operations, ensuring thread-safe set, delete, and get actions. This solution eliminated race conditions and resolved errors related to concurrent map iteration and writes, directly improving stability for high-concurrency deployments. The work involved applying a targeted patch, reviewing, and testing the changes to confirm effectiveness. Utilized Go as the primary language, leveraging skills in concurrency and mutex management to deliver a robust fix that reduces production incidents and improves overall reliability.