During September 2025, Eel Baz focused on build system configuration for the zml/zml repository, addressing a critical issue affecting macOS ARM64 builds. He resolved persistent build failures by updating the SHA256 checksum for the pjrt-cpu_darwin-arm64 artifact to v13.0.0, ensuring artifact integrity and reproducible builds. Working primarily with Starlark and Bazel, Eel’s targeted bug fix prevented future checksum drift and reinforced cross-platform reliability for the PJRT tarball. Although the work was limited to a single bug fix rather than feature development, it demonstrated careful attention to build reproducibility and artifact management within a complex, multi-platform build environment.