Ask HN: Interview questions/topics for a Windows developer

I lead a small team of web developers. We have recently been tasked to continue development on a Windows application that is already in production. None of us are Windows devs. The person who wrote the application is still with the company on another team, but they're not a Windows dev either. We've always known that we'd need that expertise eventually, but events in recent weeks have highlighted that.

We have some applicants in the pipeline, I was wondering whether there were good ways to gauge Windows skills without having that knowledge myself.