I was originally scheduled for a reasonably quick interview at Turbine Kinetics with a handful of engineers. As the day went on, I was introduced to more and more people, which I was okay with as I took it as a good sign. Interview lasted far longer than scheduled. I ended up meeting people onwards up the chain until reaching head of the facility, and had a good discussion with him. I left at the end of the workday with an offer heavily implied as coming to me, implied by the head of the facility. Had a good interview experience.
Then I had no follow-up for weeks. Upon reaching back out to them again, was told "we never had an open position, we just interview regularly to get an idea of who's out there".
Don't waste my time (if that statement is true), and don't lie to me (if they didn't want to hire me).