If I had to sum up the process in one work it would be 'Thorough'
There are a few different stages of the interview process, first meeting with the Chief of Staff, then management for the role you're applying for, followed with a homework assignment, a third interview with the respective team you'd be working with reviewing that homework assignment, and the final stage meeting with the CEO.
Yes, it's a bit lengthy, but as an applicant this process gives you the opportunity to see the company culture, meet everyone you'd be working closely with, and really gives you an idea if you'd enjoy working there.