Worked on the dart-lang/core repository to deliver a performance-oriented refactor of path handling logic using Dart for backend development. Consolidated the path-joining process by introducing a private helper method, which streamlined both join() and absolute() functions. This approach eliminated redundant validation steps and reduced intermediate memory allocations, resulting in faster path resolution and lower memory churn in critical code paths. By centralizing logic, the refactor also simplified future maintenance of fixed-parameter join signatures and reduced the risk of regression. The work focused on quality and maintainability, providing clear migration benefits without introducing separate bug fixes during the period.