3 rounds + 1 written assignment prior, 2 rounds with the same manager and one with the CEO. Overall, a pleasant experience, interviewer was nice enough to provide me feedback on the interview when I asked after being rejected. It was an insightful 3 interviews although, it was really dragged out. Really liked the company and the work they do so was a bit disappointed when I did not get the job but really kudos to the hiring manager for giving me a good sense of the company.