Lately Ive been going the other way as an interviewer. I try to get the candidate to deeply explain their system design; starting point, requirements, conflicting priorities, compromises, etc. Alternatively we can pivot slightly to solving the same class of problem with my system.

I can almost always find a relevant overlap between my background and theirs, which helps. And (I think) its beneficial for them to talk about their experience and existing decision making as opposed to hypotheticals. As a bonus you can also gauge the ability to communicate complex or nuanced ideas in a succinct manner.