bazel-monorepo-expert

bazel-monorepo-expert

Keyword: monorepo | Platforms: gemini,claude,codex

Bazel Monorepo Expert Skill - Structuring, managing, and optimizing large-scale Bazel workspaces with multiple services, shared libraries, and complex dependency graphs.

Core Mandates

• Single Source of Truth: One workspace for all services and shared libraries.
• Strict Visibility: Default private, explicitly expose only public APIs.
• Dependency Hygiene: No circular dependencies, no diamond dependency conflicts.
• Consistent Tooling: Same Java version, same linter, same test framework across all packages.
• Incremental Builds: Granular targets for fast incremental builds and cache hits.

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Workspace Structure

Recommended Layout

my-monorepo/
├── WORKSPACE.bazel (or MODULE.bazel)
├── .bazelrc
├── .bazelignore
├── .bazelversion
├── BUILD.bazel (root)
├── platforms/
│   └── BUILD.bazel
├── toolchains/
│   └── BUILD.bazel
├── third_party/
│   └── BUILD.bazel
├── common/
│   ├── utils/
│   │   ├── src/main/java/...
│   │   ├── src/test/java/...
│   │   └── BUILD.bazel
│   ├── models/
│   │   └── BUILD.bazel
│   └── proto/
│       └── BUILD.bazel
├── services/
│   ├── user/
│   │   ├── src/main/java/...
│   │   ├── src/test/java/...
│   │   ├── src/main/resources/
│   │   ├── k8s/
│   │   ├── helm/
│   │   └── BUILD.bazel
│   ├── order/
│   │   └── BUILD.bazel
│   └── payment/
│       └── BUILD.bazel
├── libs/
│   ├── auth/
│   │   └── BUILD.bazel
│   ├── messaging/
│   │   └── BUILD.bazel
│   └── observability/
│       └── BUILD.bazel
└── tools/
    ├── buildifier/
    ├── linters/
    └── scripts/

Root BUILD.bazel

# BUILD.bazel (root)
exports_files([".bazelrc", "MODULE.bazel"])

# Test suite for all tests in the repo
test_suite(
    name = "all_tests",
    tests = [
        "//common/utils:all_tests",
        "//common/models:all_tests",
        "//services/user:all_tests",
        "//services/order:all_tests",
        "//services/payment:all_tests",
        "//libs/auth:all_tests",
        "//libs/messaging:all_tests",
    ],
)

# Build all services
filegroup(
    name = "all_services",
    srcs = [
        "//services/user:user-service_image",
        "//services/order:order-service_image",
        "//services/payment:payment-service_image",
    ],
)