I chatted with a recruiter at a Materials Research Society career fair. Eight weeks later, I received an email and set up a phone call with a technical group manager. That call was mostly technical and questions were asked to see if I was intelligent.
An on sight interview followed. A delayed flight threw off the timing of the interviews (which were ~5 one-on-one conversations), and I spent 20 minutes alone in a conference room waiting for someone to show up. Again, questions were mostly technical with some problem solving think-on-my-feet exercises. It was Friday afternoon, and some of the interviewers were visibly exhausted and had not read any of my application materials. They appeared to dislike their jobs, and by the end of the day it was evident that I was a poor cultural fit for the company.
I sent a "thank you for your time" follow-up email and never heard anything again.