It was a 4 stage process and each stage is about 45mins - 1hr long.
1- Introduction interview with the CTO
2- Technical interview giving a presentation on an architecture you've worked on, they will ask you about design decisions, why did you use x, is there a better approach?...
3. Cultural fit interview were they will ask you some questions about you and you will have some time to ask them questions
4. Interview with the CEO, similar to the previous stop but you will go through your previous jobs and ask you about your managers and how you were doing, feedback what you liked or disliked...