I've always just tried to hold a conversation with the candidate, what they think their strengths are weaknesses are and a little probing.
This works especially well if I don't know the area they're strongest in, because then they get to explain it to me. If I don't understand it then it's a pretty clear signal that they either don't understand it well enough or are a poor communicator. Both are dealbreakers.
Otherwise, for me, the most important thing is gauging: Aptitude, Motivation and Trustworthiness. If you have these three attributes then I could not possibly give a shit that you don't know how kubernetes operators work, or if you can't invert a binary tree.
You'll learn when you need it; it's not like the knowledge is somehow esoteric or hidden.
This works especially well if I don't know the area they're strongest in, because then they get to explain it to me. If I don't understand it then it's a pretty clear signal that they either don't understand it well enough or are a poor communicator. Both are dealbreakers.
Otherwise, for me, the most important thing is gauging: Aptitude, Motivation and Trustworthiness. If you have these three attributes then I could not possibly give a shit that you don't know how kubernetes operators work, or if you can't invert a binary tree.
You'll learn when you need it; it's not like the knowledge is somehow esoteric or hidden.