Yeah, they should be able to code. However a DP question is a bad one to ask, for it is not representative of the kinds of problems they solve day to day. This

Yeah, they should be able to code. However a DP question is a bad one to ask, for it is not representative of the kinds of problems they solve day to day. This is like asking a programmer about deep security questions related to ssl or the details of the latest kernel bug or spectre. It is good to know those for a programmer but it is a poor signal for the job at hand. Light on my front porch might illuminate my backyard, but nobody chooses a bulb on that basis. I would use another light for my backyard.