I have worked on some of the most supposedly reliable codebases on earth (compilers) for several decades, and most of the code in compilers is pretty bad.

And most of the code the compiler is expected to compile, seen from the perspective of fixing bugs and issues with compilers, is absolutely terrible. And the day that can be rewritten or improved reliably with AI can't come fast enough.

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jacquesm 4 hours ago | parent [-]

I honestly do not see how training AI on 'mountains of garbage' would have any other outcome than more garbage.

I've seen lots of different codebases from the inside, some good some bad. As a rule smaller + small team = better and bigger + more participants = worse.

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fooker 4 hours ago | parent | next [-]

The way it seems to work now is to task agents to write a good test suite. AI is much better at this than it is at writing code from scratch.

Then you just let it iterate until tests pass. If you are not happy with the design, suggest a newer design and let it rip.

All this is expensive and wasteful now, but stuff becoming 100-1000x cheaper has happened for every technology we have invented.

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jacquesm 33 minutes ago | parent [-]

Interesting, so this is effectively 'guided closed loop' software development with the testset as the control.

It gives me a bit of a 'turtles all the way down' feeling because if the test set can be 'good' why couldn't the code be good as well?

I'm quite wary of all of this, as you've probably gathered by now: the idea that you can toss a bunch of 'pass' tests into a box and then generate code until all of the tests pass is effectively a form of fuzzing, you've got some thing that passes your test set, but it may do a lot more than just that and your test set is not going to be able to exhaustively enumerate the negative cases.

This could easily result in 'surprise functionality' that you did not anticipate during the specification phase. The only way to deal with that then is to audit the generated code, which I presume would then be farmed out to yet another LLM.

This all places a very high degree of trust into a chain of untrusted components and that doesn't sit quite right with me. It probably means my understanding of this stuff is still off.

	▲	fooker 28 minutes ago \| parent [-]
		You are right. What you are missing is that the thing driving this untrusted pile of hacks keep getting better at a rapid pace. So much that the quality of the output is passable now, mimicking man-years of software engineering in a matter of hours. If you don’t believe me, pick a project that you have always wanted to build from scratch and let cursor/claude code have a go at it. You get to make the key decisions, but the quality of work is pretty good now, so much that you don’t really have to double check much.

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simonw 4 hours ago | parent | prev [-]

That's why the major AI labs are really careful about the code they include in the training runs.

The days of indiscriminately scraping every scrap of code on the internet and pumping it all in are long gone, from what I can tell.

	▲	jacquesm 4 hours ago \| parent \| next [-]
		Well, if as the OP points out it is 'all garbage' they don't have a whole lot of choice to discriminate.
	▲	fooker 4 hours ago \| parent \| prev [-]
		Do you have pointers to this? Would be a great resource to understand what works and what doesn't.