Worked on the swiftlang/swift-build repository to deliver Metal 4.0 deployment target support, focusing on enhancing the build system for future GPU feature integration. The work involved updating compiler and linker specifications to recognize Metal 4.0, modifying .xcspec files, and adding relevant localization strings. Using Swift and XML, the developer ensured the build system could automatically detect and configure Metal 4.0 compilation paths. This feature enables projects to target the latest Metal Shading Language capabilities, streamlining the adoption of new GPU features. The approach demonstrated a strong grasp of build systems and compiler configuration within a modern development workflow.