[namrog84]

While I do agree with you. To play the counterpoint advocate though.

What if we get to the point where all software is basically created 'on the fly' as greenfield projects as needed? And you never need to have complex large long lived codebase?

It is probably incredibly wasteful, but ignoring that, could it work?

[fwip]

That sounds like an insane way to do anything that matters.

Sure, create a one-off app to post things to your Facebook page. But a one-off app for the OS it's running on? Freshly generating the code for your bank transaction rules? Generating an authorization service that gates access to your email?

The only reason it's quick to create green-field projects is because of all these complex, large, long-lived codebases that it's gluing together. There's ample training data out there for how to use the Firebase API, the Facebook API, OS calls, etc. Without those long-lived abstraction layers, you can't vibe out anything that matters.

[theshrike79]

In Japan buildings (apartments) aren't built to last forever. They are built with a specific age in mind. They acknowledge the fact that houses are depreciating assets which have a value lim->0.

The only reason we don't do that with code (or didn't use to do it) was because rewriting from scratch NEVER worked[0]. And large scale refactors take massive amounts of time and resources, so much so that there are whole books written about how to do it.

But today trivial to simple applications can be rewritten from spec or scratch in an afternoon with an LLM. And even pretty complex parsers can be ported provided that the tests are robust enough[1]. It's just a metter of time someone rewrites a small to medium size application from one language to another using the previous app as the "spec".

[0] https://www.joelonsoftware.com/2000/04/06/things-you-should-...

[1] https://simonwillison.net/2025/Dec/15/porting-justhtml/

[techblueberry]

> But today trivial to simple applications can be rewritten from spec or scratch in an afternoon with an LLM. And even pretty complex parsers can be ported provided that the tests are robust enough[1]. It's just a metter of time someone rewrites a small to medium size application from one language to another using the previous app as the "spec".

This seems like a sort of I dunno chicken and the egg thing.

The _reason_ you don't rewrite code is because it's hard to know that you truly understand the spec. If you could perfectly understand the spec then you could rewrite the code, but then what is the software, is it the code or the spec that writes the code. So if you built code A from spec, rebuilding it from spec I don't think qualifies a rewrite, it's just a recompile. If you're trying to fundamentally build a new application from spec when an old application was written by hand, you're going to run into the same problems you have in a normal rewrite.

We already have an example of this. Typescript applications are basically rewritten every time that you recompile typescript to node. Typescript isn't the executed code, it's a spec.

edit: I think I missed that you said rewrite in a different language, then yeah fine, you're probably right, but I don't think most people are architecture agnostic when they talk about rewrites. The point of a rewrite is to keep the good stuff and lose a lot of bad stuff. If you're using the original app as a spec to rewrite in a new language, then fine yeah, LLM's may be able to do this relatively trivially.

[arkensaw]

I don't know about Japan - I vaguely recall reading that most buildings over there are built with wood (even the big ones) and that this is historically something to do with rebuilding after Tsunamis and earthquakes.

Buildings in most other countries in the world ARE built to last forever, and often renovated, changed, extended and modified long after the incept date until, because needs change, and destroying them to start over is complete overkill (Although some people do these "large scale refactors" - they're usually rich).

> It's just a metter of time someone rewrites a small to medium size application from one language to another using the previous app as the "spec".

I have no doubt of this. I'm sure it's happening already. But the whole point of long term stable applications is that they are tried and tested. A port done in an afternoon by an LLM might be great, but you can't know if it has problems until it has withstood the test of time.

[fwip]

Sure, and the buildings are built to a slowly-evolving code, using standard construction techniques, operating as a predictable building in a larger ecosystem.

The problem with "all software" being AI-generated is that, to use your analogy, the electrical standards, foundation, and building materials have all been recently vibe-coded into existence, and none of your construction workers are certified in any of it.

[techblueberry]

I don't think so. I don't think this is how human brains work, and you would have too many problems trying to balance things out. I'm thinking specifically like a complex distributed system. There are a lot of tweaks and iterations you need for things to work with eachother.

But then maybe this means what is a "codebase". If a code base is just a structured set of specs that compile to code ala typescript -> javascript. sure, but then, it's still a long-lived <blank>

But maybe you would have to elaborate on, what does "creating software on the fly" look like,. because I'm sure there's a definition where the answer is yes.

[damethos]

I have the same questions in my head lately.