bazel-build-optimization

SKILL.md

Bazel Build Optimization

Production patterns for Bazel in large-scale monorepos.

When to Use This Skill

Setting up Bazel for monorepos

Configuring remote caching/execution

Optimizing build times

Writing custom Bazel rules

Debugging build issues

Migrating to Bazel

Core Concepts

1. Bazel Architecture
workspace/
├── WORKSPACE.bazel       # External dependencies
├── .bazelrc              # Build configurations
├── .bazelversion         # Bazel version
├── BUILD.bazel           # Root build file
├── apps/
│   └── web/
│       └── BUILD.bazel
├── libs/
│   └── utils/
│       └── BUILD.bazel
└── tools/
    └── bazel/
        └── rules/

2. Key Concepts

Concept
Description

Target
Buildable unit (library, binary, test)

Package
Directory with BUILD file

Label
Target identifier //path/to:target

Rule
Defines how to build a target

Aspect
Cross-cutting build behavior

Templates and detailed worked examples

Full template library and detailed worked examples live in references/details.md. Read that file when you need the concrete templates.

Best Practices

Do's

Use fine-grained targets - Better caching

Pin dependencies - Reproducible builds

Enable remote caching - Share build artifacts

Use visibility wisely - Enforce architecture

Write BUILD files per directory - Standard convention

Don'ts

Don't use glob for deps - Explicit is better

Don't commit bazel-* dirs - Add to .gitignore

Don't skip WORKSPACE setup - Foundation of build

Don't ignore build warnings - Technical debt