# Developer Guide

Documentation for contributors and maintainers.

## Testing

- [Testing Guide](testing_philosophy.md) — Principles, cost-awareness, and practical guide

## Contributing

See [CONTRIBUTING.md](../../../CONTRIBUTING.md) for setup, code style, and PR process.

## Additional Resources

- [Type Annotation Policy](../TYPE_ANNOTATION_POLICY.md)
- [User Guide](../user_guide/index.md)
- [API Reference](../api.md)