Building an app with AI feels great right up until it doesn’t.
For a while you can keep going. A bug appears, you paste the error into the tool, it suggests a fix, and you move on. Then one day the loop stops working. The fixes create new bugs. The app gets slower. You start avoiding certain buttons because you are not sure what they do anymore.
That is usually the moment a founder emails us.
You do not need a computer science degree to know when your app is in trouble. The signs are behavioural, not technical. Here are the five we hear most often, and how to tell the difference between a rough patch and a real problem.
Sign 1: Users report bugs you cannot reproduce
A user tells you the checkout failed. You try it yourself, and it works fine. You assume they made a mistake. Then two more people report the same thing.
Bugs that only appear for some people are a classic symptom of AI-generated code. They usually come from something the happy path never touches: a slow network, an empty field, a user in a different timezone, a second browser tab, an account created before you changed the signup flow.
The demo works because you always test it the same way. Real users do not.
When you cannot reproduce a bug, you cannot fix it by guessing. This is the point where trial-and-error stops paying off, because you are patching symptoms you have never actually seen. A professional will reproduce it properly, usually by checking logs and error tracking that your app probably does not have yet.
Sign 2: Adding one feature breaks another
You ask the tool to add a small feature. It does. But now the login page is broken, or the dashboard shows the wrong data, or an old form has stopped submitting.
This is one of the most reliable signs that the underlying code has no real structure. In a healthy codebase, separate features are separate. Changing one thing does not quietly reach across and break something unrelated.
When everything is tangled together, every change becomes a gamble. AI tools are especially prone to this because they often duplicate logic instead of reusing it, so the same rule ends up written five slightly different ways in five different files. Fix it in one place and the other four keep misbehaving.
If you have started to dread adding features because you do not know what will break, that dread is information. The code is telling you it needs restructuring, not more patches.
Sign 3: The app is slow and nobody knows why
At first the app was quick. Now pages take a few seconds to load, and it is getting worse as you add more data.
Slowness that grows with usage almost always points to how the code talks to the database. AI tools frequently write queries that are fine for ten records and painful for ten thousand. They fetch more than they need, they loop when they should ask once, and they skip the indexes that make databases fast.
The tricky part is that you cannot see any of this from the outside. The app looks the same. It just feels heavier. And because there is no obvious error, the tool has nothing to react to when you ask it for help.
If your app is getting slower and the answer is always “add more server power,” that is a workaround, not a fix. Someone needs to look at what the code is actually doing.
Sign 4: You are afraid to deploy changes
There is a specific feeling that tells us an app is in trouble. The founder has a change ready, it works on their laptop, and they still do not want to press deploy.
That fear is rational. It usually means past deploys have gone wrong, there is no safety net, and there is no quick way to undo a bad release. Professional software has tests, staging environments, and a rollback plan precisely so that shipping a change is boring instead of frightening.
Vibe-coded apps rarely have any of that by default. The tool builds the feature. It does not build the confidence that the feature is safe to ship.
If deploying makes your stomach drop, the problem is not your nerve. It is the missing infrastructure around your code.
Sign 5: You cannot explain what the code does
This is the quietest sign and often the most serious.
You built the app, but you could not honestly explain how the authentication works, where user data is stored, or what happens when a payment fails. The tool wrote it, it worked, and you never had to understand it.
That is fine until something goes wrong, a user asks a data question you are legally required to answer, or you want to bring in help and cannot say what already exists.
Not understanding your own code is not a personal failing. Vibe coding is designed to let you skip that understanding. But there is a difference between not needing to know the details and not being able to find them out. If nobody, including the tool, can give you a clear account of how the important parts work, you are flying blind.
So what counts as normal?
None of these signs on their own means disaster. Early apps are messy. Every product has bugs. A slow page or a scary deploy can be a one-off.
The pattern to watch for is the loop breaking down. Vibe coding works because there is a feedback cycle: something breaks, the tool helps, you move on. You need professional help when that cycle stops closing. The fixes stop sticking. The bugs outpace the patches. You spend more time firefighting than building.
If you recognise two or three of these signs together, that is the loop failing.
What to do next
You do not have to rewrite everything, and you almost never should. Most of the apps we see are worth saving. The problems are concentrated in a few predictable places: error handling, validation, permissions, and the database.
A good first step is a proper assessment. Not another prompt to the tool, but a person reading the actual code to tell you what is solid, what is risky, and what it would take to fix. That turns a vague feeling of “something is wrong” into a specific list you can act on.
The founders who get this right are not the ones who never hit these signs. They are the ones who recognise them early, before a data breach or a launch-day crash forces the issue.
Recognise a few of these in your own app? Get a free code review. We will read your code and tell you honestly what needs fixing, and what does not.