Measured legacy Python code complexity, refactored the pricing logic into a strategy-based design, and validated the change with metrics, benchmarks, and correctness tests.
- Use AI tools to safely refactor legacy code
- Measure code complexity before and after refactoring
- Track performance improvements through metrics
- Validate refactoring changes with automated tests
- Apply DevOps best practices for code quality monitoring
- Basic Python programming knowledge
- Understanding of code complexity concepts
- Familiarity with Linux command line
- Basic Git operations
- Understanding of software metrics (cyclomatic complexity, maintainability)
- Platform: Ubuntu 24.04 LTS cloud lab environment
- Host: ip-172-31-10-244
- Shell: Bash
- Primary toolchain: Python 3.12, Radon, Pylint, Pytest, pytest-benchmark, Black, isort, Git, Aider configuration
- Analyze Legacy Code Complexity
- AI-Assisted Refactoring
- Measure and Compare Metrics
lab31-ai-driven-refactor-with-metrics/
├── artifacts/
│ ├── baseline_metrics_full.json
│ ├── refactored_metrics_full.json
│ └── refactoring_impact_report.txt
├── .aider.conf.yaml
├── commands.sh
├── compare_metrics.py
├── legacy_calculator.py
├── measure_metrics.py
├── output.txt
├── refactor_instructions.md
├── refactored_calculator.py
├── test_correctness.py
├── test_performance.py
└── test_refactored_performance.py
- Radon metrics, benchmark comparison, and six correctness test cases.
- Average cyclomatic complexity reduced from 9.50 to 2.17.
- Shared-function comparison reported 75.44% overall complexity improvement.
- Maintainability Index improved from 48.07 to 59.53.
- Correctness tests passed and behavior remained functionally equivalent.
- Performance remained acceptable, with some overhead introduced by strategy dispatch.
- How to baseline code quality before changing legacy logic.
- How strategy-based refactoring can reduce nested conditionals.
- How to compare complexity, maintainability, and benchmark data together.
- Why automated correctness tests are mandatory during refactors.
Metrics-backed refactoring is useful when reducing technical debt without breaking production logic.
- Maintaining legacy business logic in Python services.
- Preparing refactor work for CI/CD quality gates.
- Justifying technical-debt cleanup with measurable evidence.
This lab was completed successfully and documented with separate source files, execution commands, runtime output, interview prep, and troubleshooting guidance.
This lab strengthened practical experience with ai-driven refactor with metrics in a hands-on Linux environment. The documented workflow, source files, and verification steps make the implementation reproducible and suitable for portfolio use.