Choosing Bazel

When considering Bazel for your project, it's crucial to understand both its strengths and challenges. This guide helps you make an informed decision by examining various aspects of Bazel adoption.

When to Choose Bazel

1. Multi-language Projects

• Unified Build System: Single tool for building Go, Rust, C++, Java, etc.
• Consistent Interface: Same commands and concepts across languages
• Shared Dependencies: Better handling of cross-language dependencies

2. Large Scale Projects

• Incremental Builds: Only rebuilds what changed
• Remote Caching: Share build artifacts across team
• Remote Execution: Distribute build load

3. Cross-platform Development

• Hermetic Builds: Same results across different machines
• Platform-specific Toolchains: Proper handling of cross-compilation
• Reproducible Artifacts: Bit-for-bit identical outputs

When to Consider Alternatives

1. Small Single-language Projects

• Added Complexity: Bazel adds overhead for simple projects
• Learning Curve: Team needs to learn Bazel concepts
• Setup Time: Initial configuration can be significant

2. Rapid Prototyping

• Quick Iterations: Native toolchains often faster for development
• Simple Dependencies: Package managers sufficient for basic needs
• Team Familiarity: Using known tools can be more productive

3. Limited Resources

• Maintenance Overhead: Keeping Bazel configuration up to date
• Training Requirements: Team needs dedicated learning time
• Infrastructure Needs: Remote caching/execution needs infrastructure

Language-specific Considerations

Go

• Pros:
  • Excellent cross-compilation support
  • Good integration with Gazelle for BUILD file generation
  • Works well with proto/gRPC
• Cons:
  • More complex than go mod
  • Additional step for adding dependencies
  • Some Go tooling assumes go mod

JavaScript/TypeScript

• Pros:
  • Fine-grained dependency graph
  • Works well with monorepos
  • Good integration with Node.js ecosystem
• Cons:
  • Complex ecosystem with many build tools
  • npm/yarn workflow differences
  • Development mode performance

Rust

• Pros:
  • Good cross-compilation support
  • Works well with cargo-raze
  • Excellent C/C++ integration
• Cons:
  • Less mature than Cargo
  • Some crates assume Cargo
  • Additional configuration needed

Build Tool Integration

Gazelle

• Role: Generates BUILD files from source code
• Benefits:
  • Automates dependency management
  • Keeps BUILD files in sync
  • Handles proto generation
• Limitations:
  • Language-specific (primarily Go)
  • May need manual adjustments
  • Configuration can be complex

Migration Strategy

Gradual Adoption

1. Start with new components
2. Migrate one language at a time
3. Use build bridges during transition

Common Challenges

• Developer workflow changes
• CI/CD integration
• Third-party dependency management

Success Factors

• Team buy-in and training
• Clear migration plan
• Good documentation

Making the Decision

Consider these questions:

1. Is your project complex enough to benefit from Bazel?
2. Do you have the resources for adoption?
3. Will the long-term benefits outweigh the initial costs?
4. How will it impact your development velocity?
5. What's your team's capacity for learning new tools?

The decision to use Bazel should be based on your specific needs, resources, and long-term goals. While it offers powerful features for large, complex projects, it may not always be the best choice for simpler scenarios.