Worked on the buildkite/agent repository to deliver Working Directory Management for Hooks, enabling deterministic execution environments across complex pipelines. Developed a new Job API endpoint, client method, and CLI command in Go to allow users to set, validate, and persist working directories for hooks and command phases. The implementation ensures robust path handling, with relative paths resolved against the hook’s directory and absolute paths enforced by the API. Leveraging backend development and testing skills, the solution propagates directory changes across hooks using environment updates, enhancing reliability for both shell and polyglot hooks and supporting more advanced pipeline configurations.