I would want to treat it as a customer interview, asking them about specific situations where they had to negotiate customer needs, how they decide what feature

I would want to treat it as a customer interview, asking them about specific situations where they had to negotiate customer needs, how they decide what features are proper and what are extraneous, and how they get buy-in from the team to implement [desired, necessary, relevant] stuff. Have they ever worked on a product before it had achieved a sense of product-market-fit, and if so, how did they help it get there? When they did not feel content in their role, what was lacking? And when they did feel content in their role, what were the great elements that set it a cut above the rest?