A lot of steps in the interview HR, Long 3 part assesment + Culture essay, interview with hiring manager, interview with a random person in the company, interview with the CEO.
Overall, I think everyone was great, except the CEO, people keep telling me that he's nice, But during the interview, I asked, "What kind of people do you like to work with?", His answer was, "People who would work 16 hours a day without compensation." To me, this is an obvious red flag, and make do what you will with this information.