Worked on Bazel-related repositories, focusing on backend development and build system reliability. In the bazelbuild/continuous-integration repo, implemented flexible Bazel version matching for RBE preconfiguration, allowing toolchain selection based on major versions and providing user warnings for clarity. Improved the robustness of Buildkite CI pipelines by refining matrix attribute handling, ensuring correct processing of lists and dictionaries to reduce pipeline errors. In the bazelbuild/rules_cc repository, addressed Windows runtime issues by fixing the copying of non-system DLLs to the appropriate subdirectory. Utilized C++, Python, and CI/CD practices to enhance build stability and streamline upgrade and deployment processes.