I remember talking to Brendan Gregg about how he conducted technical interviews, back when we both worked at Netflix. He told me that he was interested in identifying the limits of a candidate’s knowledge, and how they reacted when they reached that limit. So, he’d keep asking deeper questions about their area of knowledge until they reached a point where they didn’t know anymore. And then he’d see whether they would actually admit “I don’t know the answer to that”, or whether they would bluff. He knew that nobody understood the system all of the way down.

I think this is the nut of building out a skilled development team. You need different people at different levels who know their area of expertise well and who are willing to admit where it ends, such that they can reach out to the next guy to step in and assist.

But also, you need the Full Code Stack as it were. Or, at least, you need a way to know where your blind spots are and understand the limit of your capacity. Otherwise, you run the risk of an “innovator” asking why they can’t just dump canola oil into their gas tank or how come you can’t just use hydrogen instead of helium for your balloon. And worse - plowing ahead because nobody outside of their cubicle stepped in to stop them.

You run the risk of destroying a lot of your own hard work - and possibly a lot of other people’s hard work - because you didn’t realize your own limits or know where to go to exceed them.