Even from the POV of the interviewer it's a great question. I'd give my answer then brainstorm with the interviewee about how they would propose solving that p

Even from the POV of the interviewer it's a great question. I'd give my answer then brainstorm with the interviewee about how they would propose solving that problem. Would you feel comfortable asking an interviewee the same question about their last job? It could give a sense of how they think / why they are looking for a new spot but might be a little invasive.