Vibe coding is when you build an app by describing what you want in plain English and letting an AI tool write the code. You type a prompt, the tool generates a working feature, you look at it, and you move on to the next prompt.
No computer science degree required. No years learning syntax. You describe the login page, the tool builds it. You describe the dashboard, the tool builds that too.
It’s a genuinely useful way to get from idea to working product fast. Founders who couldn’t have built anything themselves five years ago are now shipping real apps in a weekend using Cursor, Bolt, Lovable, v0, or Replit Agent.
The apps also tend to have bugs. Not eventually. Often within the first week of real users touching them.
This isn’t a knock on the tools or the people using them. It’s a side effect of how the process works, and it’s worth understanding before you find out the hard way.
How AI coding tools actually work
An AI coding tool doesn’t understand your business. It predicts what code is likely to come next, based on patterns it learned from a huge amount of existing code.
When you ask for a signup form, it has seen thousands of signup forms and produces something that looks like a good one. Same with a checkout flow, a dashboard, or an API endpoint. The output is often clean, uses modern conventions, and runs without errors the first time you test it.
That’s the part that trips people up. Code that runs without errors looks finished. But “runs without errors” and “handles every situation your users will throw at it” are two very different bars, and only one of them gets checked automatically.
The tool built what you asked for. It rarely builds what you forgot to ask for.
The “works on my machine” problem
You test the app yourself. You click through the signup flow, add an item to the cart, submit the contact form. Everything works.
Then a real user shows up and does something you never tried: pastes an emoji into the name field, hits back button mid-checkout, uploads a 40MB image instead of a profile photo, or opens the app on a phone with a spotty connection. Something breaks.
This happens because you tested the happy path, the sequence of clicks that goes exactly as planned. AI-generated code is usually good on the happy path, because that’s what the prompt described and that’s what you tried when you checked the work.
Everything off the happy path is where the gaps show up: errors, edge cases, weird input, slow networks, users doing things in an unexpected order. Nobody wrote a prompt for “what happens when the API call times out,” so nothing handles it.
This is not really about the AI tool being bad at its job. It’s about the shape of the request. When you describe a feature, you’re describing what success looks like. You’re not describing every way it could fail, because most of us don’t think in those terms when we’re excited about shipping something. A developer who has been burned by a 3am support ticket learns to ask “what if this fails halfway through” almost automatically. A first-time founder prompting an AI tool usually doesn’t, and the tool won’t ask on your behalf unless you tell it to.
Five hidden issues that show up after launch
A handful of problems come up again and again in vibe-coded apps, usually invisible until someone hits them:
No error handling. When something fails — a database call, a payment, an image upload — the app either crashes, shows a blank screen, or silently does nothing. There’s no message telling the user what went wrong or what to do next.
Missing input validation. Forms accept whatever gets typed into them. No check on email format, no limit on field length, no filtering of unexpected characters. This causes bad data in your database and, in worse cases, security holes.
Broken permissions. A user can see or edit data that isn’t theirs, because the permission check either doesn’t exist or only exists in the part of the app you can see, not the part that actually talks to the database.
State management chaos. The app shows stale or contradictory information — an item still marked “in cart” after checkout, a balance that doesn’t update after a payment — because different parts of the app aren’t staying in sync.
Hardcoded values that don’t scale. Fine for a demo with three test accounts, but they fall apart the moment your app has real data volume or more than a handful of users.
None of these show up when you’re the only person using the app. All of them show up once strangers start using it in ways you didn’t anticipate.
Here’s the thing that makes this tricky to catch on your own: none of these five issues cause your app to look broken in a code editor. There’s no red squiggly line under a missing permission check. The app compiles, deploys, and loads the same whether the error handling is solid or completely absent. You would need to either stumble into the failure yourself or have someone deliberately go looking for it.
Why this isn’t really the AI tool’s fault
It’s tempting to blame the tool once you find the first bug. That’s usually not fair, and it’s also not useful, because you’re going to keep using AI tools either way. They’re too good at getting you from zero to something real.
The tool did what you asked. If you asked for a login form, you got a login form. If your prompt didn’t mention what happens when someone enters a password 200 characters long, the tool had no reason to think about that case, because you didn’t raise it and the vast majority of example login forms it learned from didn’t handle it either.
This is closer to hiring a very fast, very literal contractor. Tell them to build a deck, and they’ll build exactly the deck you described. If you didn’t mention weatherproofing, don’t be surprised when it warps in the rain. The fix isn’t to stop hiring contractors. It’s to know which questions to ask, and to have someone check the work before you invite guests over.
When it’s time to bring in a professional
A vibe-coded app is a genuinely solid way to get to a first version. The mistake is treating that first version as production-ready without anyone checking the assumptions underneath it.
If your app is still just for you, or a handful of friendly testers, you probably have time. If you’re about to launch, take payments, store user data, or scale past a small test group, it’s worth having someone look at what’s under the hood before that happens instead of after.
The signs that it’s time: you’re seeing errors you can’t explain, users are reporting things that “shouldn’t be possible,” you’re not sure what happens if two people submit a form at the same time, or you genuinely don’t know what your app does when something goes wrong. None of these are things you have to figure out alone.
Wondering if your vibe-coded app has hidden bugs? Get a free assessment, and we’ll tell you exactly what needs fixing before your users find it for you.