Had a pleasant interview of multiple rounds, and everything was positive: they even started to call and check all my references, and one of my references said it was a very positive call and it sounded like they were going to hire me. Then I had a almost spontaneous feeling additional interview AFTER my on-site with a manager/director level who was condescending. They then soon after sent a rejection, saying that I was a good candidate but they had a better alternative candidate. Seems they made some kind of "last minute" decision to reject me. I would have preferred instead more up front clarity, especially if you're going to start contacting references and make it sound like you are going to hire me.