Guillaume upgraded the Codspeed Core and Codspeed Google Benchmark Compat modules to version 2.1.0 within the bazelbuild/bazel-central-registry repository, focusing on enhancing Bazel build performance and compatibility for downstream projects. He implemented new dependency management strategies and module development practices, leveraging JSON and YAML for configuration and automation. The release process was streamlined with automated publishing to the Bazel Central Registry, and continuous integration validation ensured build stability without introducing critical defects. Guillaume’s work provided a more robust upgrade path for Codspeed modules, addressing compatibility risks and supporting improved workflows for Bazel-based development environments and their consumers.