Worked on enhancing build efficiency and cross-repository collaboration for the facebook/buck2 and facebook/buck2-prelude projects by enabling cross-constraint build sharing for Rust libraries. Implemented support for incoming transitions in rust_library, allowing builds to be shared across different constraint variations by stripping irrelevant constraints, which reduces duplicate compilations and accelerates CI feedback for multi-constraint configurations. Extended this capability to third-party crates, improving ecosystem support and build graph configurability. Collaborated closely with peers through code reviews and pull requests, leveraging expertise in Rust, build system development, and dependency management to deliver features that streamline build processes across multiple repositories.