Even then, the senior developer/architect "social networking app" graph algorithms stuff has its limits as well. Mathematicians come up with great algorithms, n

Even then, the senior developer/architect "social networking app" graph algorithms stuff has its limits as well. Mathematicians come up with great algorithms, not software developers; we just use 'em. And this makes sense because those are two entirely different roles. Imo it's more important that you can break down an existing best-in-class algorithm for x task and have your prospective dev answer questions about it/how they would use it, etc. Expecting every senior dev to be a best-in-class top mathematician as well as having a handle on the ever-changing language/library/ops/etc stacks is just crazy. I'd never expect a senior dev on my teams to just know something like that, but I would expect that given a task they can do their research, find good candidates and understand the pros/cons of each approach. Because our power is in our ability to learn & use; the stuff that we already know is a bonus.