2 days, thorough personality interview, super nice people in all levels (HR, professional leader, higher level HR). Had good chemistry, they were email-responsive, called me whenever needed to update on anything. Moverover, they were very honest about what they were looking for, and respectful (they said it's all about finding the right "fit" and that I'm skillful, shared with me whatever concerns they had and really went with me over and over about anything that might be a red flag for them. Anyways If I didn't get an offer I wouldn't be offended because the feedback was so clear and honest).