[ssharp]

My own personal, small sample size experience has shown that if I start questioning things early on in the interview, I can predict fairly well whether or not the company will be a good fit or not. I try not to jump to conclusions but even initial emails and phone calls can make for pretty strong clues.

If I sense during an interview that things aren't going to be a good fit, I still try and finish the interview graciously. There is no use burning any bridge, even if it's one you're 100% certain you'll never use. One trick I do to keep myself from seeming aloof or displeased is to start asking questions about the industry. At this point, I know I don't want the job and probably don't care about the culture, but learning something about an industry you may not know much about could be useful down the line.