Boy was I wrong. My first question was "Name the most common data structures you use day to day". He stayed silent for a bit and then said "What, do you want me to just list them?" I said yes. After some more silence he said he couldn't recall any. The fact that he said "list" was particularly ironic.
I kind of gave up on expecting used-to-be software developers to have retained a single bit of knowledge from their time as a dev after they've moved on to "leadership" or "management". I believe it's important for technical leadership to understand technical problems and their solutions in broad strokes, but it seems I'm mostly in the minority in the real world. That interview (and trying to hire for that role) really showed me how little engineering leaders remember about software.
