Worked on the rust-lang/cargo repository to enhance the warning experience during the cargo publish process, specifically addressing missing package metadata. Developed a feature that introduces registry-based conditional logic to tailor and validate warnings, ensuring that developers receive accurate feedback depending on the registry context. Implemented baseline tests in Rust to confirm the reliability of these warnings and fixed an issue where warnings were not generated correctly when a valid sourceId was present. This backend development effort improved package management workflows by reducing friction during publishing and strengthening metadata integrity, resulting in a more dependable experience for Rust crate maintainers.