As a very senior dev and having worked in good number of startups, including YC backed startups, I can tell you that the hardest part is rarely technical for most SaaS. It's actually validating the idea, market, and business model.

If he can get 10 or 20 paying customers, then it's easy to find money to fix or scale the code.

I agree there, but the problem I’m pointing out is you can’t fix a problem you don’t see as a problem in the first place.

This type of nonsense from Anthropic isn’t helpful whatsoever.

If you can't see the problem, it doesn't matter for an early startup; the only thing that matters is what users complain about or request and getting more users paying you. Everything can be fixed later once the idea itself has been validated.

Data breaches, financial errors, and the like for an early stage company are a death sentence. That’s the type of error I’m suggesting, not some flakey CSS.

Severely overestimating it.

Death knell is not solving a problem in the first place. Almost everything is negotiable if you solve a valuable problem that people are willing to pay you to solve.