> because the crucial change with LLMs is that you don’t use a formal language anymore to specify what you want, and get a deterministic output from that

You don't just code, you also test, and your safety is just as good as your test coverage and depth. Think hard about how to express your code to make it more testable. That is the single way we have now to get back some safety.

But I argue the manual inspection of code and thinking it through in your head is still not strict coding, it is vibe-testing as well, only code backed by tests is not vibe-based. If needed use TLA+ (generated by LLM) to test, or go as deep as necessary to test.