I only did HR interview and technical tests(2x2 hours simplify SQL and Python). I got called in for a technical interview shortly after. On the day of the interview, they called me to postpone it, which is fine, happens, but it was already very last minute. It got postponed a whole week. I found good reviews about the company(CEO looked very well spoken, down to earth and intelligent) and I was looking forward to learn more about them personally. On second try, they called me again on the day of the interview to postpone it. I told them I had an offer already, I was only waiting for this interview to see how it goes, but to be honest, I think I know everything that I need to know, so I declined it. In my opinion, this is very unprofessional, I can't think of a situation where I would willingly put clients/customers/candidates into a position like this. Being laid-back is one thing, but wasting people's time like this is just very disrespectful. If this process was fine with them, I am afraid the day-to-day workings of the company must be in chaos.