[josephv]

I had to interview a manager or two as a senior dev and then interviewed countless people for manager, supervisor, and dev jobs as a manager.

I think the best thing to focus on is hiring a manager that knows a little bit about the processes you guys use day-to-day. If you're an agile team, ask about agile; a requirement document team, ask about documentation experience. Processes sort of follow some high-level patterns due to the large accreditation bodies that profit from selling their own flavors.

Have they managed QA or been involved with continuous integration and automated testing? What task-management systems have they used? Are they interested in promoting strong architecture, is production support a priority; or ask them to list out a set of priorities related to product delivery, production support, architecture, customer service, which helps with discovering any underlying philosophies more than really giving any direct information. Give an example of a time they resolved a conflict.

Asking about what the technology stack was for the team they managed is always good as well. If they can explain it coherently they weren't just doing performance reviews and checking time logs to make sure people were at their desks.

Just some ideas off the top of my head.