Anyone saying 10x as a serious claim is clearly using a round number and vibes; however, even if it were so, AI getting popular 3 years ago does not mean what you say.
The earliest used models in this category would easily 10x (what did I just say) the creation of one-off short scripts, but you're not writing a 30-year app out of just a bunch of short scripts.
The METR time horizons graph suggests we can now get 10x (ahem) speedup on solving most coding problems that take us a few hours and about half of problems that take 2 days. Amdahl's law bites: even infinity speedup on half your problems is only 2x overall.
If you let an LLM loose, with a huge budget, what's the biggest artefact it can make before it drowns under the weight of bad decisions? The C compiler and web browser headlines a while back? The maths papers we see now that solve problems which stumped the maths world for decades?
But this is the other side of the same coin: teamwork. One person getting a thing made in twelve months vs a team of a hundred, you can scale up fast with money when you have a proof of concept, and an LLM can make a lot of proofs of a lot of concepts even in free accounts.
LLM-assisted software engineering seems to be very efficient if you have a deterministic target. (bun rewrite from zig to Rust, 100% Node.js compatibility, pnpm compatibility -- https://github.com/oven-sh/bun/pull/38333)
Problem with that is that it's not proper rust code, it's some kind of franken zig style rust port.
The actual hard part is getting it into idiomatic, safe rust, and I don't believe the LLM port makes the full transition any easier than doing things the old fashioned way: a dual lang code base like Linux.
And compiler generated assembly code is ugly and spaghetti, unlike beautiful hand-crafted human written assembly code, the kind you see in ffmpeg codecs, ...
Doesn't matter.
It does matter, because that's the entire point of the language. You know, memory safety?
The vibe coded rust port did not get them any closer to full compiler verified memory safety. They still need to go file by file, bit by bit, and make it memory safe, at which point, why not just do that from zig.
My pushback on that would be that all of the "engineering" concering a rewrite was already done the first time around. It's a glorified translation.
I do agree that the port would've taken a lot longer without LLMs though.
And how long will it take to rewrite the Rust rewrite to idiomatic safe Rust?