Starschema interview questions

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.

The interview took two rounds, first was on phone, second was on site. Friendly interviewer, nice office in Budapest. Technical questions based on the CV, and proffesional background, projects what you have been worked on.