# ADR-0002: Technology Stack Rationale

> "The best tool for the job is the one you know how to use."
> — **Unknown**

## Status
Accepted

## Context
When designing the seedling template, we need to choose the optimal technology stack for modern Python development. Each tool choice has significant implications for developer experience, performance, and maintainability.

## Decision
Select specific technologies based on performance, developer experience, and modern Python best practices.

## Consequences

### **Copier vs Cookiecutter**

#### **Why Copier?**
- **Jinja2 templating**: More powerful than Cookiecutter's limited templating engine
- **Better dependency management**: Handles template updates and dependencies more effectively
- **Modern Python support**: Built with modern Python practices and type hints
- **Version control integration**: Better git integration and update handling
- **Conditional templating**: Advanced logic for conditional file generation
- **Template inheritance**: Support for template inheritance and composition

#### **Cookiecutter Limitations**
- **Limited templating**: Basic Jinja2 features only
- **Update challenges**: Difficult to update existing projects
- **Python 2 legacy**: Originally designed for Python 2
- **Limited extensibility**: Harder to extend with custom logic

### **uv vs pip/poetry**

#### **Why uv?**
- **Performance**: 10-100x faster than pip for dependency resolution
- **Lockfile advantages**: Reproducible builds with uv.lock
- **Modern Python tooling**: Built for modern Python development
- **Modern Python tooling**: Built specifically for modern Python development
- **Cross-platform**: Works consistently across all platforms
- **Single tool**: Replaces pip, virtualenv, and other tools

#### **pip Limitations**
- **Slow dependency resolution**: Can take minutes for complex projects
- **No lockfile**: Reproducible builds require additional tools
- **Limited caching**: Less effective caching mechanisms
- **Platform differences**: Different behavior across platforms

#### **poetry Limitations**
- **Complexity**: Over-engineered for many use cases
- **Lockfile issues**: Sometimes produces inconsistent lockfiles
- **Performance**: Slower than uv for dependency resolution
- **Limited extensibility**: Harder to extend with custom logic

### **Nox vs tox**

#### **Why Nox?**
- **Python-native**: Built specifically for Python projects
- **Session management**: Clean separation of different tasks
- **CI integration**: Perfect integration with GitHub Actions
- **Extensible**: Easy to add new sessions and tasks
- **Modern design**: Built with modern Python practices
- **Better error handling**: More informative error messages

#### **tox Limitations**
- **Complex configuration**: Overly complex for simple use cases
- **Legacy design**: Built for older Python development patterns
- **Limited extensibility**: Harder to extend with custom logic
- **Performance**: Slower than Nox for many operations

### **Just vs Make**

#### **Why Just?**
- **Cross-platform compatibility**: Works on Windows, macOS, and Linux
- **Dependency management**: Handles task dependencies automatically
- **Readability**: Simple, readable syntax
- **No dependencies**: Single binary, no Python installation required
- **IDE integration**: Works well with modern IDEs
- **Modern design**: Built with modern development practices

#### **Make Limitations**
- **Unix-centric**: Primarily designed for Unix-like systems
- **Complex syntax**: Arcane syntax and rules
- **Limited Windows support**: Poor support on Windows
- **No dependency management**: Manual dependency specification
- **Legacy tool**: Designed for C/C++ development

### **Sphinx vs MkDocs**

#### **Why Sphinx?**
- **Documentation standards**: Industry standard for Python documentation
- **Extensibility**: Rich ecosystem of extensions
- **Hosting integration**: Perfect for GitHub Pages deployment
- **Search functionality**: Built-in search capabilities
- **Versioning**: Support for multiple documentation versions
- **API documentation**: Excellent autodoc support

#### **MkDocs Limitations**
- **Limited extensibility**: Fewer extensions available
- **Markdown only**: Limited to Markdown format
- **Less Python-specific**: Not designed specifically for Python
- **Limited API docs**: Poor support for API documentation
- **Search limitations**: Less powerful search functionality

### **pre-commit-ci vs Manual Enforcement**

#### **Why pre-commit-ci?**
- **Automated quality enforcement**: Runs quality checks on every PR
- **Team collaboration**: Ensures consistent code quality across team
- **Auto-fix capabilities**: Automatically fixes formatting issues
- **GitHub integration**: Seamless integration with GitHub workflows
- **Configurable**: Flexible configuration for different project needs
- **Free for public repos**: No cost for public repositories

#### **Manual Enforcement Limitations**
- **Human error**: Relies on developers remembering to run checks
- **Inconsistent**: Different developers may use different tools
- **Time-consuming**: Manual process takes time and effort
- **No guarantees**: No guarantee that quality checks are run
- **Team coordination**: Difficult to coordinate across team

## Implementation Strategy

### **Phased Rollout**
1. **Phase 1**: Core template with basic functionality
2. **Phase 2**: Advanced features and optimizations
3. **Phase 3**: Enterprise features and integrations

### **Migration Path**
- **From Cookiecutter**: Clear migration guide and tools
- **From pip**: Gradual migration with uv compatibility
- **From tox**: Direct replacement with Nox
- **From Make**: Simple Justfile conversion

### **Training and Documentation**
- **Comprehensive documentation**: Detailed guides for each tool
- **Video tutorials**: Step-by-step video guides
- **Community support**: Active community and support channels
- **Best practices**: Documented best practices and patterns

## Related ADRs
- [ADR-0001: Template Design Philosophy](./0001-template-design.md)
- [ADR-0003: Architecture Decisions](./0003-architecture-decisions.md)

## References
- [Copier vs Cookiecutter Comparison](https://copier.readthedocs.io/en/stable/faq.html#how-does-copier-compare-to-cookiecutter)
- [uv Performance Benchmarks](https://docs.astral.sh/uv/getting-started/installation/)
- [Nox vs tox Comparison](https://nox.thea.codes/en/stable/)
- [Just vs Make](https://just.systems/)
- [Sphinx vs MkDocs](https://www.sphinx-doc.org/en/master/)
- [pre-commit-ci Benefits](https://pre-commit.ci/)