The Joe Reis Show Why AI Won't Fix Your Legacy Code & The Dangers of "Vibe Coding" w/ Marianne Bellotti
Aug 14, 2025
In this engaging discussion, Marianne Bellotti, author of "Kill It With Fire" and an expert in legacy systems, tackles the misconception that AI can easily fix aging software. She warns against the pitfalls of 'vibe coding' and stresses the necessity of understanding a codebase's cultural context. Marianne also sheds light on the disconnect between AI's promises and practical coding realities, and the critical need for a thoughtful approach to technology that balances human insights with innovative tools.
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Code As Cultural Artifact
- Legacy systems encode organizational culture and past decisions, not just technical debt.
- Marianne treats old code like an archaeological artifact to decode past abstractions and choices.
Start With Tests Then Logs
- Start exploring foreign codebases with tests first, then documentation, then logs, then the code itself.
- Use logs and common transactions to trace behavior before refactoring or rewriting.
Modernize Only After Organizational Fit
- Modernization is a trade-off driven by hiring, culture, and organizational incentives.
- Choose rewriting or training based on whether the org values hiring and long-term maintenance.
