During October 2025, Michael Kilby enhanced security across four Swift open-source repositories by implementing least-privilege access controls for GitHub Actions workflows. In projects such as swiftlang/github-workflows and apple/swift-nio, he reconfigured workflow YAML files to restrict permissions to read-only access, reducing the risk of unauthorized modifications by automated processes. Using YAML and leveraging CI/CD and DevOps best practices, Michael’s changes preserved automation while improving governance and auditability. His work addressed the need for secure-by-default automation in repositories like swiftlang/swift-format and swiftlang/swift-syntax, demonstrating a focused approach to workflow permission hardening without introducing new bugs or regressions.