At a glance

Vibe coding means describing what you want, accepting whatever comes back because it appears to work, and shipping it without anyone on your side genuinely understanding the code.

For a prototype, that is a superpower. For software that holds other people's data, it is a liability. The useful question is not whether vibe coding is good or bad. It is which of those two things you are actually building, and whether you noticed when one quietly turned into the other.

Let us define it without sneering

Vibe coding is building software by conversation. You describe the outcome, the AI produces the code, you run it, and if it does roughly what you wanted you move on. Nobody reads the implementation. The vibe is the specification.

A lot of developers say this with a curled lip. We are not going to, because the honest truth is that vibe coding has put working software into the hands of people who would otherwise have had none.

Ideas that would have died in a notebook now exist. Founders who could never have afforded a prototype have something to show. Internal tools that were never worth a developer's week now get built on a Tuesday afternoon. That is a genuinely good thing and pretending otherwise is just snobbery.

Where the line is

The line is not about how the code was written. It is about what happens if the code is wrong.

Three questions settle it:

  • Does it hold data that belongs to someone else? Customer records, payment details, anything personal. If yes, a mistake is no longer just your problem.
  • Does anyone else depend on it? Staff, customers, another business. If people are relying on it working, downtime has a cost beyond your own irritation.
  • Does it need to still work in two years? If yes, someone will have to change it, and that someone needs to be able to understand it.

Answer no to all three and vibe coding is fine. Genuinely fine. Build the thing.

Answer yes to any of them and you have crossed into territory where "it seems to work" is not a good enough standard.

What changes when real people arrive

Software behaves completely differently with one user than with two hundred, and almost none of that difference shows up while you are building it.

Two people click the same button at the same moment and you get duplicate records, or a number that has been counted twice, or a booking sold to both of them. A table with ten rows and a table with two hundred thousand rows are the same code and wildly different experiences. A missing permission check is invisible until the day one customer sees another customer's information.

None of that is exotic. It is the ordinary stuff of production software, and it is exactly the stuff a demo cannot reveal.

The drift problem

Here is what actually happens, and it is worth being ready for.

Nobody decides to cross the line. There is no meeting. The weekend project gets a handful of users, then a few paying ones. Somebody adds a login. Somebody stores an address. Six months later there are forty accounts, real money moving through it, and a piece of software nobody has ever read.

The code did not change character. The stakes did. That is the single most common way people end up with a serious problem, and it happens to sensible people constantly.

So what do you do about it?

If you are on the safe side of the line, carry on and enjoy yourself.

If you have drifted across it, the fix is not usually a rebuild. It is getting someone to read what you have, find the parts that matter, and put proper foundations under the bits that are now load-bearing. That is a far smaller job than people fear, and it gets smaller the earlier you do it.

What you should not do is carry on hoping. Software problems of this kind do not stay the same size. They wait until you are successful and then present the whole bill at once.

If you want the fuller explanation of the term and what it does and does not mean, we have written up what vibe coding actually is separately.

None of this is anti-AI. As we put it at the start of this series, AI is a brilliant typist and a terrible architect. Vibe coding is what happens when you let the typist decide.

Built something on the vibes and now slightly worried about it? Our AI Code Audit is a fixed-price £495 review that tells you plainly what you are dealing with, or get in touch for a no-pressure conversation.