Cardino interview questions

Extremely long process. 1st interview is with a technical person - 1 hour - general overview of my experiences. 2nd interview - 1.5 hours of technical conversation - very in depth, "under the hood" questions. I was asked to also do a 2h live coding session as the 3rd step (with the same person from 2nd round). After both technical steps I received a feedback. I felt the feedback fair but in some places it was trumped up. Eg. during live coding I was asked to write an API, I was presented with option to write it as Java class or to do it through OpenApi. I selected the first option and later in feedback found out that I'm rusty with OpenApi... Nevertheless I received information that I got through the interviewing process and I'm only missing a 30 minute call with the founder. Few hours before the set call I got an email that the position has been taken. I have never seen this level of unprofessionalism during my career. If I went to the last call and the other person was selected - I would be ok with it (there can always be someone better), but the fact that I had a set time for the final call and got a rejection 12-14 prior to it is just disrespectful. Waste of time.