During April 2025, Kyrtzidis focused on improving the swiftlang/swift-driver repository by addressing a critical issue in SwiftScanCAS related to content-addressable storage (CAS) size limiting. He refactored the deinitialization logic to ensure the active CAS instance correctly received the size limitation setting, resolving a bug where the size limit was not enforced due to the order of database closure. To prevent future regressions, he introduced an automated test, testCASSizeLimiting, which verifies the correct application of size constraints. His work demonstrated depth in system programming, build systems, and testing, leveraging Swift to enhance reliability and maintainability in the build process.