zlacker

>>martin+(OP)
> I helped one recently almost one-shot[3] converting a 30 sheet mind numbingly complicated Excel financial model to Python with Claude Code.

I'm sure Claude Code will happily one-shot that conversion. It's also virtually guaranteed to have messed up vital parts of the original logic in the process.

>>decima+lc
It depends on how easily testable the Excel is. If Claude has the ability to run both the Excel and the Python with different inputs, and check the outputs, it's stunningly likely to be able to one-shot it.

>>linsom+4d
Something being simultaneously described as a "30 sheet, mind-numbingly complex Excel model" and "testable" seems somewhat unlikely, even before we get into whether Claude will be able to test such a thing before it runs into context length issues. I've seen Claude hallucinate running test suites before.

>>AlotOf+4e
It compacted at least twice but continued with no real issues.

Anyway, please try it if you find it unbelievable. I didn't expect it to work FWIW like it did. Opus 4.5 is pretty amazing at long running tasks like this.

>>martin+Ye
I think the skepticism here is that without tests or a _lot_ of manual QA how would you know that it did it correctly?

Maybe you did one or the other , but “nearly one-shotted” doesn’t tend to mean that.

Claude Code more than occasionally likes to make weird assumptions, and it’s well known that it hallucinates quite a bit more near the context length, and that compaction only partially helps this issue.

>>moregr+Ag
If you’re porting some formulas from one language to another, “correct” can be defined as “gets the same answers as before.” Assuming you can run both easily, this is easy to write a property test for.

Sure, maybe that’s just building something that’s bug-for-bug compatible, but it’s something Claude can work with.