700k LoC of human written code is probably like 2M LoC of LLM "slop". That's probably around 8M tokens. Assuming a single fable agent that one shots the new source code at 30 tok/s, that's 74 hours. Of course it needs wayyy more tokens because it wouldn't one shot it, plus the reasoning tokens. Generation speed would be faster because you'd have many simultaneous agents though.

Bun rewrite took 6 days of coding and was a similar number of LoC, so I think a couple of weeks is definitely reasonable, although you probably need more than 5 Claude subs.

It's way more than 8M tokens. That might be around the amount of the raw output, but there's going to be tons of tool calls, back and forth... it's probably more like 100M+ tokens.

> Bun rewrite took 6 days of coding and was a similar number of LoC, so I think a couple of weeks is definitely reasonable, although you probably need more than 5 Claude subs.

Bun had numerous standardized and extensive javascript test suites to validate the slop code against. I doubt paint.net has test coverage anywhere near that complete, and without it using LLMs to rewrite something is a much larger risk.

Besides which, Bun claims the rewrite took 6 days but they took months after that to finish hammering out the bugs and actually ship, so I don't really buy the original price tag or timeline on their rewrite.