"Ask them to explain in detail, a small part of the product. Yes! In detail! ... Everything is explainable in layman’s terms…" - so now you dependent on the teaching/explaining talent rather than code.
I've never heard anything as helpful for learning as the Feynman technique: https://fs.blog/2021/02/feynman-learning-technique/
The article's mention of "best practices" rings incredible true. If it's a "best practice" you should be able to easily list a half dozen reasons why. Otherwise you don't really understand what you're talking about.
> Feynman was a truly great teacher. He prided himself on being able to devise ways to explain even the most profound ideas to beginning students. Once, I said to him, “Dick, explain to me, so that I can understand it, why spin one-half particles obey Fermi-Dirac statistics.” Sizing up his audience perfectly, Feynman said, “I’ll prepare a freshman lecture on it.” But he came back a few days later to say, “I couldn’t do it. I couldn’t reduce it to the freshman level. That means we don’t really understand it.”
https://kottke.org/17/06/if-you-cant-explain-something-in-si...