During April 2026, Gwynne focused on backend development for the swiftlang/swift-build repository, addressing cross-platform code signing issues using Swift. She implemented a targeted fix that prevents the copying of code signing extended attributes on non-Darwin platforms, directly reducing build failures and platform-specific regressions. This change improved the reliability and consistency of builds in non-Darwin environments by eliminating incorrect attribute propagation. Gwynne’s work required a detailed understanding of platform differences and build system internals, resulting in a more unified approach to code signing. Her contribution, while scoped to a single bug fix, demonstrated depth in backend engineering and cross-platform development.