Couldn't take an article seriously that started with the author claiming that code he writes by hand is "100% correct" Bruh
There are two steps to writing the program: building a model in your head to map understanding to algorithms, and then implementing the algorithm in code (and of course this can get recursive if the algorithm relies on other high-level mechanisms, like data structures).
I have found that most of the time, the kind of bugs that unit tests find are typos, i.e. mistakes in the second step; but the errors that actually cost time to resolve are errors in understanding, i.e. the first step.
They can't be found with testing or verification because what it means for code to be correct depends on the specification, and the error is that the specification itself is incorrect. Asking an LLM to check this one specific part of the software is thus useless, and whole-program analysis is not cheap enough to employ at this point.
So what about avoidance? When I say hand-written code is 100% correct (or at least approaches that number), I mean that with experience, I learn more about which models tend to be correct, and thus avoid bugs of the latter kind by construction. Of course typos still exist, which is why I write unit tests, and I expect LLMs to be able to find them as well; but I believe the only way to avoid incorrect models is to learn stuff by doing, failing and failing again, figuring out nitty-gritty low-level details, until at some point you become an expert in that area and know what to use.