How do you keep a vibe-coded MVP from becoming unmaintainable?

How the discipline gets added back

Vibe coding gets you to a working prototype fast. What it skips is everything that keeps a codebase maintainable later: the reasoning behind choices, the check that a change actually does what it claims, the guard against two changes contradicting each other. CatWrangler puts those back as you build, not as cleanup afterward.

• Decisions are captured as you go — the choice, the reasoning, and the alternatives ruled out, bound to the exact code they govern. Two years later you can still see why the code is the way it is.
• Every change is validated before it lands — it must cover the decision it claims, and it must build and test, so incoherent or broken work never merges.
• Before building, the system surfaces code and decisions that already do the job — so you extend what exists instead of filling the codebase with duplicates.
• You describe a change in plain language and get exactly the right files and functions with the decisions behind them, so you keep moving at prompting speed.

Technical debt with a login screen

A prototype becomes unmaintainable when nobody remembers why anything was done, duplicated paths multiply, and a broken change can slip in unnoticed. Vibe-Engineering is vibe coding with the discipline of real engineering kept intact: you build at the speed of plain-language prompting, but every decision is captured with its reasoning, every change is validated before it lands, and the why behind the code is never lost. That is the difference between a real product and a demo that happens to have users.