Kirill Yakimovich contributed to the bazelbuild/rules_swift repository by delivering a targeted update to Runfiles.swift, addressing Swift 6 compatibility issues. He applied code refactoring and regex adjustments, introducing conditional compilation to support multiple Swift versions and refining indentation for improved readability. Working in Swift, Kirill focused on maintaining core infrastructure as the language evolved, ensuring that build failures were minimized for users upgrading to Swift 6. His work emphasized maintainability and business value, enabling smoother adoption of new tooling. The update was co-authored, reflecting collaborative development and traceability, and demonstrated depth in adapting codebases to changing language requirements.