João Pereira contributed to the duckduckgo/macos-browser repository by focusing on code quality and release engineering over a two-month period. He addressed a SwiftLint warning in SyncDiagnosisHelper.swift by refining spacing within a dictionary literal, ensuring the codebase met linting standards without altering its functional behavior. Using Swift and xcconfig, João maintained CI stability and code cleanliness through targeted lint-only refactoring. In addition, he managed a release version bump to 334, aligning packaging metadata with CI/CD pipelines to support stable deployments. His work demonstrated careful attention to build management, code formatting, and linting, providing a solid foundation for future development.