Even ignoring determinism, with traditional source code you have a durable, human-readable blueprint of what the software is meant to do that other humans can understand and tweak. There's no analogy in the case of "don't read the code" LLM usage. No artifacts exist that humans can read or verify to understand what the software is supposed to be doing.

Not only that but compiler optimizations are generally based on rigorous mathematical proofs, so that even without testing them you can be pretty sure it will generate equivalent assembly. From the little I know of LLM's, I'm pretty sure no one has figured out what mathematical principles LLM's are generating code from so you cant be sure its going to right aside from testing it.

or he will find a way to get the AI to create harnesses so it becomes stable. The lack of imagination and willingness to experiment in the HN crowd is AMAZING me and worrying me at the same time. Never thought a group of engineers would be the most conservative and close minded people I could discuss with.

We can tell you weren't around for the advent of compilers. To be fair, neither was I since the UNIX c compiler came out in '68 and was by far not the first compiler. Modern comilers you can make that claim about, but early compilers weren't.

I've wondered if people who write detailed specs, are overly detailed, are in a regulated industry, or even work with offshore teams have success more quickly simply they start with that behavior. Maybe they have a tendency to dwell before moving on which may be slightly more iterative than someone who vibecodes straight through.

I wonder if electrical engineers felt this way about the reliability of the silicon crystal lattice their circuits rely upon…

> The big difference is that compilation is deterministic: compile the same program twice and it'll generate the same output twice.

That's barely true now. Nix comes close, but builds are only bit-for-bit identical if you set a bunch of extra flags that aren't set by default. The most obvious instability is CPU dispatch order (aka modern single computer systems are themselves distributed, racy systems) changes the generated code ever so slightly.

We don't actually care, because if one compiled version of the code uses r8 for a variable but a different compilation uses r9 for that variable, it doesn't matter because we just assume the resulting binary works the same either way. R8 vs r9 are implementation details that don't matter to humans. See where I'm going with this? If the LLM non-deterministically calls the variable fileName one day, and file_name the next time it's given the same prompt, yeah language syntax purists are going to suffer an aneurysm because one of those is clearly "wrong" for the language in use, but it's really more of an implementation detail at this point. Obviously you can't mix them, the generated code has to be consistent in which one it's using, but if compilers get to chose r8 one day and r9 the next, and we're fine with it, why is having the exact variable name that important, as long as it's being used correctly?