Vibe Coding Technical Debt: Refactor or Rewrite Your App?

Refactor. In almost every case, a vibe-coded app with real users should be cleaned up in place, one piece at a time, not rewritten from scratch. A rewrite is justified only in a few specific situations, which I list below. And before you do either, check whether the code is actually what's holding the product back, because usually it isn't.

Here's how to make the call, and how to refactor without breaking the app people already use.

What technical debt looks like in a vibe-coded app

Technical debt is the extra cost every future change carries because of shortcuts taken earlier. In a hand-written codebase, those shortcuts were usually deliberate. In a vibe-coded one, nobody decided to take them. The AI produced code that worked in the demo, and you accepted it.

The symptoms are recognizable:

• The same logic lives in several places. You fix a pricing bug on one screen and it's still there on another.
• Every prompt breaks something unrelated. You ask for a small change and a different feature stops working.
• Nobody can explain how a part works, including you.
• Files keep growing. One component handles data fetching, business rules and layout.
• Dead features and abandoned experiments are still in the code, still running.
• No tests, so the only way to check a change is to click through the app by hand.

Duplication is the one that shows up most. GitClear's 2025 code quality research, which analyzed 211 million changed lines of code from 2020 to 2024, found the share of changes that were refactoring fell from 25% in 2021 to under 10% in 2024, while copy/pasted lines rose from 8.3% to 12.3%. GitClear sells code analysis tools, so weigh it accordingly, but it matches what you see in most AI-built codebases: new code gets added, and existing code rarely gets consolidated.

First, check whether it's a code problem at all

Founders reach for a rewrite when the product isn't working: the code is messy, the app isn't growing, so the mess must be the cause. Usually it isn't.

Messy code makes the app slower and riskier to change. It doesn't stop people from wanting it. If users aren't reaching the value or won't pay, a clean codebase will have the same problems with better folder names.

When I joined Balkanza, a social dating app, it was vibe-coded and had no revenue. What grew it to 25K+ users and $3K in monthly revenue was focusing on value and impact: cutting what didn't matter and doubling down on what did.

So before deciding anything about the code, answer two questions:

1. Is the code stopping users from getting value? Crashes in the core flow, data loss, pages that time out. That's a code problem, and it's urgent.
2. Is the code stopping you from shipping the changes users need? If every change takes a week and breaks two other things, debt is now the bottleneck.

If the answer to both is no, the code isn't your problem yet. Work on why the app isn't making money first, and keep the code changes to what that work needs.

Refactor or rewrite: how to decide

Situation	Refactor	Rewrite
The app works, but changes are slow and fragile	✓
Security holes: exposed keys, missing access control	✓ Fix them now
Duplicated logic, giant files, dead code	✓
You're still searching for what users value	✓ Minimal cleanup only
The platform can't do what the product needs (e.g. a web-only builder when you need native mobile features)		✓
The data model is fundamentally wrong and every feature fights it	Try first	Often
The app is small, has few users and little data to migrate	Either	Cheap enough
The tool or stack is being discontinued or you can't export the code		✓

The pattern: refactor when the problem is the shape of the code. Consider a rewrite only when the problem is the foundation it stands on.

When a rewrite is actually justified

Rewrites have a bad reputation for good reason. Joel Spolsky's essay Things You Should Never Do, Part I is about Netscape deciding to rewrite its browser from scratch, which left it without a major release for years while competitors kept shipping. His core point still holds: old code that works contains fixes for problems you've forgotten you had, and a rewrite throws them away.

For a vibe-coded app, a rewrite is reasonable when most of these are true:

• You know what users value, because people are using and paying for a specific core flow.
• The current foundation (platform, framework, data model) blocks that core flow, and you can name exactly how.
• You've tried refactoring the blocking part and it didn't work.
• The app is small enough that the rewrite takes weeks, not months.
• You can keep the old version running for users until the new one is ready.
• Someone who can read code will own the new version, not just prompt it into existence again.

If you can't tick the first box, don't rewrite. You'd be rebuilding a product you don't understand yet, and you'll recreate the same debt with a new set of prompts.

How to refactor a vibe-coded app without breaking it

This is the process I'd follow, in this order:

1. Freeze new features for a short cleanup window. Refactoring while adding features is how vibe-coded apps end up worse.
2. Fix security first. Exposed secrets, missing row-level security, unverified payment webhooks. These aren't debt, they're liabilities. My production-readiness checklist covers what to look for.
3. Write down the core flow: the few steps from signup to a user's first result. This must never break.
4. Add tests for that flow before touching the code. End-to-end tests that click through the core flow are enough to start, and AI tools write them well. They pin down what the app does today, so you know immediately when a change breaks it.
5. Delete what nobody uses. Features with no weekly users are pure cost, and deleting code is the fastest refactor there is.
6. Consolidate duplicates. Move logic that exists in several places (pricing, permissions, date handling) into one. Ask the AI to find duplicates, then review the merge yourself.
7. Split the biggest files. Separate data access, business rules and interface. One file, one job.
8. Change one module at a time, and deploy after each. Small deploys mean that when something breaks, you know which change did it.

Using AI to refactor safely

AI tools can refactor well, but only with tighter instructions than they were given when they wrote the code:

• Give it one narrow task per prompt: "move the price calculation from these three files into one function, don't change behavior."
• Tell it what not to touch. Name the files and behavior that must stay the same.
• Run the tests after every change. Don't accept a refactor because the AI says it worked.
• Read the diff. If you can't follow it, the change is too big. Ask for a smaller one.

If you do rewrite, replace it in slices

Even a justified rewrite shouldn't be a big-bang switch. Martin Fowler's Strangler Fig pattern describes the safer way: build the new system gradually around the old one, move one piece of functionality at a time, and retire the old parts as the new ones take over.

For a small app, that might mean:

1. Move the data to a database the new version can own, and point the old app at it.
2. Rebuild the core flow first, and send new users to it.
3. Move existing users once the new flow matches the old one.
4. Rebuild or drop the remaining features, one at a time, based on whether anyone uses them.

You keep a working product the whole time, and can stop halfway if the old code turns out to be fine.

How to stop the debt from coming back

• Keep a cleanup budget: a fixed slice of every week for tidying the code you touched.
• Keep a short rules file in the repo and give it to your AI tool with every task: where shared logic lives, and "reuse existing functions before writing new ones."
• Run the core-flow tests on every deploy, and delete failed experiments promptly.

Common questions

Can AI fix its own technical debt?

Partly. AI tools are good at mechanical refactors (moving code, renaming, splitting files, writing tests) when the task is narrow and there are tests to check the result. They're bad at deciding what the code should look like, because they don't know which parts matter to your users. That decision is yours, or a developer's.

Should I hire a developer to clean up my vibe-coded app?

Bring in an experienced engineer once you have paying users, store sensitive data, or the app has become too fragile to change. A review of the architecture and security usually tells you whether you need a refactor, a partial rewrite or neither. If the real question is what to build next rather than how the code is written, you need product help more than engineering help, which is what a fractional product manager does.

Is it faster to rewrite with AI than to refactor?

It's faster to generate a new version. It isn't faster to reach one that handles every edge case the old one quietly handled and migrates existing data without losing users. Writing the code was never the slow part of a rewrite.