Codebase Classification Skill

Analyze and classify codebases before making changes to ensure appropriate development approach.

Overview

Before modifying any codebase, classify it to determine whether to:

• Follow existing patterns (Disciplined)
• Gradually improve while following conventions (Transitional)
• Propose improvements to legacy patterns (Legacy)
• Establish best practices from scratch (Greenfield)

Classification Types

1. Disciplined Codebase

Signals:

• Consistent code style (formatting, naming conventions)
• Comprehensive test coverage (>70%)
• Clear module boundaries and interfaces
• Type hints/annotations throughout
• Up-to-date dependencies
• Active CI/CD pipeline
• Good documentation (README, docstrings)

Approach: Follow existing patterns strictly. Don't introduce new conventions.

2. Transitional Codebase

Signals:

• Mixed code quality (some areas good, others not)
• Partial test coverage (30-70%)
• Some type hints, inconsistent usage
• Active development with modernization efforts
• Dependencies somewhat current

Approach: Follow existing conventions in touched areas. Propose improvements for new code.

3. Legacy Codebase

Signals:

• Inconsistent patterns across the codebase
• Minimal or no tests (<30% coverage)
• No type hints
• Outdated dependencies
• Complex, undocumented logic
• Possibly unmaintained

Approach: Be careful with changes. Add tests before modifying. Propose gradual improvements.

4. Greenfield Codebase

Signals:

• New project (<6 months old)
• Few files (<20 source files)
• No established patterns yet
• Minimal or no tests (but not legacy)
• Active initial development

Approach: Establish best practices from the start. Set up proper structure, testing, CI.

Quick Classification Checklist

Run this analysis before making significant changes: