One interesting bit of context is that the author of this post is a legit world-class software engineer already (though probably too modest to admit it). Former staff engineer at Google and co-founder / CTO of Tailscale. He doesn't
need LLMs. That he says LLMs make him more productive at all as a hands-on developer, especially around first drafts on a new idea, means a lot to me personally.
His post reminds me of an old idea I had of a language where all you wrote was function signatures and high-level control flow, and maybe some conformance tests around them. The language was designed around filling in the implementations for you. 20 years ago that would have been from a live online database, with implementations vying for popularity on the basis of speed or correctness. Nowadays LLMs would generate most of it on the fly, presumably.
Most ideas are unoriginal, so I wouldn't be surprised if this has been tried already.