I don't know if I would call the Detroit market hot, it took me about 3-4 months to find a new job. However, I'm not a software developer, so rhat could also have something to do with it.
Definitely has something to do with it. I'm a software engineer in the Detroit area and the last time I switched jobs (4ish years ago), it took less than 2 weeks from the time I updated and posted my resume to signing an offer letter. With the number of calls and emails I get daily for different positions in the area, I have a feeling it would go just as quickly the next time I decide to make a move.