This kind of wisdom only comes from experience I think. Either that or higher order think. Like the article says, most of the time testing/tdd/qa is bolt on aft

This kind of wisdom only comes from experience I think. Either that or higher order think. Like the article says, most of the time testing/tdd/qa is bolt on after-the-fact. Or a big push at the end with "QA Sprints" (are you sprinting or are you examining? what exactly is a QA sprint? I know what it is). Once you get beyond "I wrote a function" and "I tested a function" and even still "I tested a function that was called by a function over the wire", you will come to a realization that no matter how edgy your edge cases, no matter how thorough your QA, there will always - ALWAYS be 0-day "undefined behavior" in certain configurations. On certain hardware. On certain kernels. It's an assurance that I guarantee that I'm almost positive it's bug free, since it passed tests, it passed human eyes, and it passed review - fingers crossed.