Start with HR interview, then technical interview, test-case, CTO interview. Question about salary, your experience, deep technical questions, test case assesment. They give you for about a week to get solution for a test case.

I applied to CTO position but I was told I could fit better as DevOps Engineer due to my CV and experience and they are looking for CTO to manage 100 Engineer although just 15 Developers are working there. However I also was interested in the DevOps Engineer position, they were doing migration and I like doing things from scratch and I liked the company very much. I did a phone interview then I was given a Business Case, which I did quickly and then was invited to meet COO and other team member for a tough 90 minutes technical interview. It wasn't hard but it was pretty long and was asked questions that are too general, theoretical or not really related to the position, but I answered with the best knowledge I could have. In same day after 2 hour of leaving the office I was told that I left good impression and they asked me to come to meet CEO in same day or tomorrow. I met the CEO one day after in 90minutes meeting, which I really enjoyed the conversation with the CEO as such cool young and intelligent person. I was looking forward to hearing a positive thing very soon, because from my perspective the interview went well and thought they would not spend that long time with me if I was screwing things up. After 2 days I was told they won't proceed with me and wasn't given any reason. I accepted their decision and asked for feedback and I was told they got to choose another person who is more senior than me. That was understable but something like that would be actually was known from screening CVs and they should contact only those with a specific seniority level. So I asked for feedback about my weaknesses and strength but I was also given a general answer but they didn't mention any weaknesses but they told me I showed strong knowledge about AWS. I was like what? isn't that you were looking for? anyway I could see that the position wasn't filled yet. They have the right to hire anybody they want but as a person who invested such amount of time doing multiple interviews, solving business cases and trying to find time in my schedule for the sake of interviews, I was expected that they invest little time too to write me meaningful feedback and not leave me with questions marks. Specially their hiring manager was working at Uber.