Worked on the Automattic/harper repository to enhance the reliability and usability of the Harper-CLI tool by addressing a key issue in its linting workflow. Focused on Rust-based command line interface development, the work involved correcting the lint exit code semantics so that the CLI exits with code 0 when no lints are found and 1 when lints are present, reducing false positives in CI pipelines. The solution included refactoring error handling to propagate errors via main() using anyhow::bail!(), improving testability and maintainability. Additional formatting updates ensured code consistency and adherence to project standards throughout the process.