
Keith Smiley engineered robust build and testing infrastructure across the modularml/mojo and modular/modular repositories, focusing on Bazel-based systems to streamline cross-platform development. He modernized build pipelines by integrating Bazel MODULE.bazel workflows, refactoring toolchains, and automating dependency management, which improved CI reliability and reduced maintenance overhead. Leveraging C++ and Python, Keith enhanced GPU testing, implemented dynamic execution strategies, and enforced package-level visibility for cleaner layering. His work included upgrading core dependencies, introducing mypy type checking for OSS, and optimizing sanitizer and environment handling. These efforts resulted in more predictable builds, accelerated iteration cycles, and improved developer experience across diverse platforms.
March 2026: Delivered cross-repo Bazel build system modernization, enabling Bazel 9.x readiness and improved cross-module compatibility. Key work includes Bazel dependency upgrades, Swift Syntax groundwork for Bazel integration, and Swift tooling index store upgrades to boost build verification. Apple tooling and Swift-related dependencies were modernized, while protocol buffers compatibility was extended across 8.x+/9.x. In addition, macOS reliability fixes improved metrics overflow handling and client-side getconf computations, improving stability for macOS builds and telemetry. Build UX improvements, including exports_files, public is_tool_configuration, and test_env overrides, reduced developer friction and accelerated iteration. CI gating and header parsing/test reliability improvements further hardened the workflow for large-scale multi-repo contributions.
March 2026: Delivered cross-repo Bazel build system modernization, enabling Bazel 9.x readiness and improved cross-module compatibility. Key work includes Bazel dependency upgrades, Swift Syntax groundwork for Bazel integration, and Swift tooling index store upgrades to boost build verification. Apple tooling and Swift-related dependencies were modernized, while protocol buffers compatibility was extended across 8.x+/9.x. In addition, macOS reliability fixes improved metrics overflow handling and client-side getconf computations, improving stability for macOS builds and telemetry. Build UX improvements, including exports_files, public is_tool_configuration, and test_env overrides, reduced developer friction and accelerated iteration. CI gating and header parsing/test reliability improvements further hardened the workflow for large-scale multi-repo contributions.
February 2026 — Key features, bugs, and impact across four repositories. Delivered focused improvements that streamline usability, bolster cross-platform build flexibility, and enhance build stability. Key features delivered include: Bazel: Remove --incompatible_lexicographical_output NOOP flag to simplify query options and reduce configuration surface. Protocol Buffers: Remove direct dependency on rules_apple and switch apple_binary to cc_binary for more consistent cross-platform builds. SwiftSyntax: Add SwiftWarningControl dependency and associated test to extend syntax library capabilities. Major bugs fixed: Rules_cc: Silence a clang warning by removing an unused argument in header parsing and fix handling of empty flags to prevent build-time errors. Overall impact: Reduced configuration surface, improved developer experience, more robust builds, and better compiler output — accelerating development workflows and reducing CI friction. Technologies/skills demonstrated: Bazel build rules and configurations, C/C++, clang flag management, dependency management and cross-repo integration, test coverage for new dependencies.
February 2026 — Key features, bugs, and impact across four repositories. Delivered focused improvements that streamline usability, bolster cross-platform build flexibility, and enhance build stability. Key features delivered include: Bazel: Remove --incompatible_lexicographical_output NOOP flag to simplify query options and reduce configuration surface. Protocol Buffers: Remove direct dependency on rules_apple and switch apple_binary to cc_binary for more consistent cross-platform builds. SwiftSyntax: Add SwiftWarningControl dependency and associated test to extend syntax library capabilities. Major bugs fixed: Rules_cc: Silence a clang warning by removing an unused argument in header parsing and fix handling of empty flags to prevent build-time errors. Overall impact: Reduced configuration surface, improved developer experience, more robust builds, and better compiler output — accelerating development workflows and reducing CI friction. Technologies/skills demonstrated: Bazel build rules and configurations, C/C++, clang flag management, dependency management and cross-repo integration, test coverage for new dependencies.
January 2026 performance highlights across modular/modular and Bazel OSS repos: stabilized and accelerated the Bazel-based build pipeline, improved cross-platform compatibility, and delivered core tooling enhancements with targeted reliability improvements. Focused on CI reliability, performance, and platform support across modular/modular, bazelbuild/bazel, bazelbuild/rules_cc, and bazelbuild/bazel-central-registry.
January 2026 performance highlights across modular/modular and Bazel OSS repos: stabilized and accelerated the Bazel-based build pipeline, improved cross-platform compatibility, and delivered core tooling enhancements with targeted reliability improvements. Focused on CI reliability, performance, and platform support across modular/modular, bazelbuild/bazel, bazelbuild/rules_cc, and bazelbuild/bazel-central-registry.
December 2025 monthly summary across the modular/modular repo and Bazel ecosystem. Key outcomes include stronger module boundaries through repo-wide package-level default_visibility, cleanup of legacy visibility, OSS typing improvements via mypy integration, and CI hardening that stabilized builds and reduced noise. Deliveries spanned multiple repos (modular/modular, bazelbuild/bazel, astral-sh/python-build-standalone, bazelbuild/rules_cc, grpc/bazel-central-registry). These changes improved maintainability, reduced surface area for misconfigurations, enabled earlier type checking for OSS users, and enhanced CI reliability and developer productivity.
December 2025 monthly summary across the modular/modular repo and Bazel ecosystem. Key outcomes include stronger module boundaries through repo-wide package-level default_visibility, cleanup of legacy visibility, OSS typing improvements via mypy integration, and CI hardening that stabilized builds and reduced noise. Deliveries spanned multiple repos (modular/modular, bazelbuild/bazel, astral-sh/python-build-standalone, bazelbuild/rules_cc, grpc/bazel-central-registry). These changes improved maintainability, reduced surface area for misconfigurations, enabled earlier type checking for OSS users, and enhanced CI reliability and developer productivity.
November 2025 (2025-11) monthly summary for modularml/mojo focused on delivering stable build infrastructure and improved runtime hygiene. The updates reduce cross-platform build issues, improve stability, and clarify sanitizer usage for faster and more reliable feature delivery.
November 2025 (2025-11) monthly summary for modularml/mojo focused on delivering stable build infrastructure and improved runtime hygiene. The updates reduce cross-platform build issues, improve stability, and clarify sanitizer usage for faster and more reliable feature delivery.
Month: 2025-10. Delivered a set of cross-repo Bazel build-system improvements and reliability fixes that accelerate CI, simplify maintenance, and strengthen platform coverage. Key highlights include modernization of Bazel configuration for OpenTelemetry C++ (MODULE.bazel adoption), central registry integration for opentelemetry-proto, and major updates to Bazel Rules Mojo with cleanup and tests. In parallel, several build/CI hardening efforts improved Xcode handling, cross-platform toolchain dynamics, and runtime-path correctness, while Apple/Linux CI reliability was boosted through VisionOS compatibility fixes and consistent symbol handling. Key business value: - Faster, more reliable builds across multiple platforms and languages. - Easier upgrade path for Bazel tooling (MODULE.bazel adoption) and central registry integration. - Reduced maintenance cost via cleanup of legacy patches, unused targets, and improved test coverage. - Improved developer experience with cross-platform toolchain improvements and better diagnostics. - Enhanced CI coverage (4x H100) and ASAN-enabled Python extensions for quicker feedback on regressions.
Month: 2025-10. Delivered a set of cross-repo Bazel build-system improvements and reliability fixes that accelerate CI, simplify maintenance, and strengthen platform coverage. Key highlights include modernization of Bazel configuration for OpenTelemetry C++ (MODULE.bazel adoption), central registry integration for opentelemetry-proto, and major updates to Bazel Rules Mojo with cleanup and tests. In parallel, several build/CI hardening efforts improved Xcode handling, cross-platform toolchain dynamics, and runtime-path correctness, while Apple/Linux CI reliability was boosted through VisionOS compatibility fixes and consistent symbol handling. Key business value: - Faster, more reliable builds across multiple platforms and languages. - Easier upgrade path for Bazel tooling (MODULE.bazel adoption) and central registry integration. - Reduced maintenance cost via cleanup of legacy patches, unused targets, and improved test coverage. - Improved developer experience with cross-platform toolchain improvements and better diagnostics. - Enhanced CI coverage (4x H100) and ASAN-enabled Python extensions for quicker feedback on regressions.
September 2025 monthly summary focusing on business value and technical achievements across the repository ecosystem. Key features delivered include: - Bazel tooling modernization in modularml/mojo: updated rules_cc and rules_mojo to latest releases, added in-tree linker driver support, and aligned mojo-kernels with mojopkgs to streamline in-tree builds and reduce maintenance overhead. - Stability and reliability improvements across Bazel/tooling: fixed bazel info usage, established stable venv paths for custom environments, implemented a workaround for symlink hacks in max/benchmark scenarios, and reverted a kernel change (RoPE) to preserve OSS compatibility. - OSS testing and toolchain readiness: enabled OSS modular_py_test targets and environment, expanded SDK test coverage across multiple Python versions, and introduced an Open Source CC toolchain workflow to improve OSS onboarding and testing consistency. - Bazel 9.x readiness and build tooling enhancements: added rules_shell dependency for sh_binary support, introduced path-mapping improvements for tblgen rules to enable action deduplication, and explored on-disk content-addressable storage optimization to boost cache-hit rates. - CI efficiency and governance: adopted BuildBuddy tagging with improved tag naming, cleaned up CI targets to remove invalid ones and ignored Metal CI, and enabled multi-GPU usage in AMD CI to accelerate validation cycles. Overall, these efforts delivered tangible business value by increasing build stability, expanding OSS participation and testing coverage, accelerating CI feedback, and laying groundwork for Bazel 9.x compatibility across multiple critical repositories.
September 2025 monthly summary focusing on business value and technical achievements across the repository ecosystem. Key features delivered include: - Bazel tooling modernization in modularml/mojo: updated rules_cc and rules_mojo to latest releases, added in-tree linker driver support, and aligned mojo-kernels with mojopkgs to streamline in-tree builds and reduce maintenance overhead. - Stability and reliability improvements across Bazel/tooling: fixed bazel info usage, established stable venv paths for custom environments, implemented a workaround for symlink hacks in max/benchmark scenarios, and reverted a kernel change (RoPE) to preserve OSS compatibility. - OSS testing and toolchain readiness: enabled OSS modular_py_test targets and environment, expanded SDK test coverage across multiple Python versions, and introduced an Open Source CC toolchain workflow to improve OSS onboarding and testing consistency. - Bazel 9.x readiness and build tooling enhancements: added rules_shell dependency for sh_binary support, introduced path-mapping improvements for tblgen rules to enable action deduplication, and explored on-disk content-addressable storage optimization to boost cache-hit rates. - CI efficiency and governance: adopted BuildBuddy tagging with improved tag naming, cleaned up CI targets to remove invalid ones and ignored Metal CI, and enabled multi-GPU usage in AMD CI to accelerate validation cycles. Overall, these efforts delivered tangible business value by increasing build stability, expanding OSS participation and testing coverage, accelerating CI feedback, and laying groundwork for Bazel 9.x compatibility across multiple critical repositories.
August 2025 highlights: Delivered cross-repo Bazel tooling modernization, expanded GPU testing capabilities, and strengthened stability/CI. Business value includes more reliable builds, faster iteration cycles, and better alignment with latest tooling, enabling teams to ship features with confidence and reducing maintenance overhead across contributor ecosystems.
August 2025 highlights: Delivered cross-repo Bazel tooling modernization, expanded GPU testing capabilities, and strengthened stability/CI. Business value includes more reliable builds, faster iteration cycles, and better alignment with latest tooling, enabling teams to ship features with confidence and reducing maintenance overhead across contributor ecosystems.
2025-07 monthly summary: Delivered across multiple repositories a major modernization of Bazel and Python tooling, enabling OSS-friendly builds and faster iteration. Implemented Bazel/PyCross tooling modernization in modularml/mojo, refreshed Python dependencies, and stabilized Mypy tooling. Strengthened Open Source Bazel build reliability with targeted fixes (uv alias, dep removals, path mapping rollback), and expanded OSS build features (python3.9 uv wrapper, disk cache, wheel build options, and open-source test infrastructure). Across the codebase, improved KBench, Mojo internal test libraries, GPU test configurations, CI, and lint/test infrastructure. These changes deliver tangible business value: faster, more reliable builds, broader wheel availability, OSS compatibility, and a stronger testing framework enabling safer deployment and easier OSS collaboration.
2025-07 monthly summary: Delivered across multiple repositories a major modernization of Bazel and Python tooling, enabling OSS-friendly builds and faster iteration. Implemented Bazel/PyCross tooling modernization in modularml/mojo, refreshed Python dependencies, and stabilized Mypy tooling. Strengthened Open Source Bazel build reliability with targeted fixes (uv alias, dep removals, path mapping rollback), and expanded OSS build features (python3.9 uv wrapper, disk cache, wheel build options, and open-source test infrastructure). Across the codebase, improved KBench, Mojo internal test libraries, GPU test configurations, CI, and lint/test infrastructure. These changes deliver tangible business value: faster, more reliable builds, broader wheel availability, OSS compatibility, and a stronger testing framework enabling safer deployment and easier OSS collaboration.
June 2025 highlights across multiple repos focused on building a more reliable, scalable, and industry-ready platform. The work spans build tooling, benchmarking, testing, and dependency hygiene, with strong emphasis on enabling cross‑platform support, faster feedback loops, and improved performance visibility.
June 2025 highlights across multiple repos focused on building a more reliable, scalable, and industry-ready platform. The work spans build tooling, benchmarking, testing, and dependency hygiene, with strong emphasis on enabling cross‑platform support, faster feedback loops, and improved performance visibility.
May 2025 performance summary: Delivered substantial Bazel/Mojo modernization and test automation across modularml/mojo and related repos, elevating build reliability and enabling broader open-source collaboration. Implemented Mojo target name aliases to simplify build configuration and expanded public repository exposure of assets and testdata tooling, improving onboarding and external usage. Migrated a large suite of tests to mojo_test across GPU, memory, layout, and stdlib modules, significantly increasing test coverage and feedback velocity while reducing flakiness. Strengthened CI and build stability with fixes to LLD path resolution, symlink handling, and infrastructure improvements, reducing flaky builds and maintenance overhead. Completed strategic refactors and layout simplifications (stdlib directory changes, tensor_internals replacements) to enable future performance gains and more consistent internal APIs. These efforts collectively improve developer productivity, accelerate feature delivery, and provide safer, faster validation for customers and external contributors.
May 2025 performance summary: Delivered substantial Bazel/Mojo modernization and test automation across modularml/mojo and related repos, elevating build reliability and enabling broader open-source collaboration. Implemented Mojo target name aliases to simplify build configuration and expanded public repository exposure of assets and testdata tooling, improving onboarding and external usage. Migrated a large suite of tests to mojo_test across GPU, memory, layout, and stdlib modules, significantly increasing test coverage and feedback velocity while reducing flakiness. Strengthened CI and build stability with fixes to LLD path resolution, symlink handling, and infrastructure improvements, reducing flaky builds and maintenance overhead. Completed strategic refactors and layout simplifications (stdlib directory changes, tensor_internals replacements) to enable future performance gains and more consistent internal APIs. These efforts collectively improve developer productivity, accelerate feature delivery, and provide safer, faster validation for customers and external contributors.
April 2025 performance summary: Across multiple Bazel-based repositories, delivered key build-system improvements, feature deliveries, and reliability improvements that enable faster integration cycles and leaner production artifacts. Highlights include SwiftSyntax C shims Bazel build integration, expanded C/C++ toolchain capabilities, cross-repo toolchain modernization and cleanup, build wrapper robustness improvements, and ONNX deprecation with test infra cleanup. These efforts improved CI stability on macOS, enhanced cross-platform compatibility, and reduced production artifacts by moving dev dependencies to development scope.
April 2025 performance summary: Across multiple Bazel-based repositories, delivered key build-system improvements, feature deliveries, and reliability improvements that enable faster integration cycles and leaner production artifacts. Highlights include SwiftSyntax C shims Bazel build integration, expanded C/C++ toolchain capabilities, cross-repo toolchain modernization and cleanup, build wrapper robustness improvements, and ONNX deprecation with test infra cleanup. These efforts improved CI stability on macOS, enhanced cross-platform compatibility, and reduced production artifacts by moving dev dependencies to development scope.
March 2025 focused on stabilizing and modernizing the toolchain and build infra across multiple repositories, delivering tangible reliability and performance improvements for developers and downstream users. The month included significant C++ toolchain enhancements, Apple-platform toolchain modernization, improved Python runfiles handling and runtime dependency semantics, and targeted code quality improvements that reduce maintenance burden.
March 2025 focused on stabilizing and modernizing the toolchain and build infra across multiple repositories, delivering tangible reliability and performance improvements for developers and downstream users. The month included significant C++ toolchain enhancements, Apple-platform toolchain modernization, improved Python runfiles handling and runtime dependency semantics, and targeted code quality improvements that reduce maintenance burden.
February 2025 monthly summary for the developer team. Focused on delivering high-impact tooling improvements across the Bazel ecosystem, stabilizing test environments, and enhancing cross-version compatibility to drive faster, more reliable builds. The work spans three repositories (rules_cc, apple_support, rules_apple) and emphasizes business value through better configurability, onboarding, and platform support.
February 2025 monthly summary for the developer team. Focused on delivering high-impact tooling improvements across the Bazel ecosystem, stabilizing test environments, and enhancing cross-version compatibility to drive faster, more reliable builds. The work spans three repositories (rules_cc, apple_support, rules_apple) and emphasizes business value through better configurability, onboarding, and platform support.
January 2025 monthly summary focusing on delivering robust Bazel-based build improvements across multiple repos, with emphasis on cross-language toolchains, registry updates, and build reliability. Key features delivered span per-file type compiler flags for Objective-C, environment/run path fixes, build configuration modernization, macOS tooling, and registry updates. Major bugs fixed include run_env with script_path handling, nested py_test runfiles, and CI stability tweaks.
January 2025 monthly summary focusing on delivering robust Bazel-based build improvements across multiple repos, with emphasis on cross-language toolchains, registry updates, and build reliability. Key features delivered span per-file type compiler flags for Objective-C, environment/run path fixes, build configuration modernization, macOS tooling, and registry updates. Major bugs fixed include run_env with script_path handling, nested py_test runfiles, and CI stability tweaks.
December 2024 performance highlights: Delivered cross-repo platform enhancements and reliability improvements centered on Bazel tooling, expanded platform coverage, and improved developer experience. Key features delivered include ARM64 Linux build support for buildbuddy via a CLI_VERSION bump to 5.0.134, environment handling improvements in aspect-build/rules_py (prevent env vars from being baked into binaries) along with env_inherit support for py_test, Bazel 7+ modernization and provider updates in bazelbuild/rules_apple, and CI stability improvements for Stardoc by pinning Bazel versions in rules_swift. Additionally, CLT/toolchain robustness improvements were added in bazelbuild/apple_support to enable CLT-only builds and safer toolchain handling. Major bugs fixed include documentation accuracy in buildbuddy cli.md, env leakage in py_binary, and test execution stability under Bazel 8.x, plus coverage environment cleanup and root-package linking fixes. These changes broaden platform support, improve build reliability, and streamline testing and release cycles, delivering tangible business value and a more maintainable codebase. Technologies/skills demonstrated include Bazel build system modernization, cross-repo CI stability, environment propagation and isolation, provider architecture refactoring, and platform-specific toolchain enhancements.
December 2024 performance highlights: Delivered cross-repo platform enhancements and reliability improvements centered on Bazel tooling, expanded platform coverage, and improved developer experience. Key features delivered include ARM64 Linux build support for buildbuddy via a CLI_VERSION bump to 5.0.134, environment handling improvements in aspect-build/rules_py (prevent env vars from being baked into binaries) along with env_inherit support for py_test, Bazel 7+ modernization and provider updates in bazelbuild/rules_apple, and CI stability improvements for Stardoc by pinning Bazel versions in rules_swift. Additionally, CLT/toolchain robustness improvements were added in bazelbuild/apple_support to enable CLT-only builds and safer toolchain handling. Major bugs fixed include documentation accuracy in buildbuddy cli.md, env leakage in py_binary, and test execution stability under Bazel 8.x, plus coverage environment cleanup and root-package linking fixes. These changes broaden platform support, improve build reliability, and streamline testing and release cycles, delivering tangible business value and a more maintainable codebase. Technologies/skills demonstrated include Bazel build system modernization, cross-repo CI stability, environment propagation and isolation, provider architecture refactoring, and platform-specific toolchain enhancements.
November 2024 performance summary for multi-repo development: Delivered key features, reliability fixes, and telemetry improvements across protobuf, Bazel Central Registry, opentelemetry-cpp, and related build tooling. Focused on stabilizing builds, improving metrics/telemetry, and ensuring cross-platform compatibility to support faster releases and better observability.
November 2024 performance summary for multi-repo development: Delivered key features, reliability fixes, and telemetry improvements across protobuf, Bazel Central Registry, opentelemetry-cpp, and related build tooling. Focused on stabilizing builds, improving metrics/telemetry, and ensuring cross-platform compatibility to support faster releases and better observability.
October 2024 monthly summary focusing on performance optimization, build-system hardening, and architectural modernization across three repos: JetBrains/rules_python, grpc/bazel-central-registry, and bazelbuild/bazel. Key wins include faster wheel patching, more reliable builds with empty glob handling, and the migration to Starlark for Objective-C attribute configuration, delivering measurable business value through faster CI, reduced resource usage, and easier maintenance.
October 2024 monthly summary focusing on performance optimization, build-system hardening, and architectural modernization across three repos: JetBrains/rules_python, grpc/bazel-central-registry, and bazelbuild/bazel. Key wins include faster wheel patching, more reliable builds with empty glob handling, and the migration to Starlark for Objective-C attribute configuration, delivering measurable business value through faster CI, reduced resource usage, and easier maintenance.

Overview of all repositories you've contributed to across your timeline