Worked on improving cache integrity in the swiftlang/swift-package-manager repository by addressing an issue where corrupted binary artifacts could persist after validation failures. Developed a private helper to accurately derive cache keys and safely evict problematic files within the observability scope, ensuring that subsequent package resolutions would re-download clean data instead of reusing corrupted artifacts. This backend development effort, implemented in Swift and supported by thorough testing, enhanced the reliability and maintainability of the package resolution process. The solution reduced user-facing errors and prevented repeated failures, contributing to a more robust and predictable experience for developers relying on package management.