First round was behavioral, second was mainly asking abstract tech questions on the technologies, the next (which I didn't make past) was the behavioral and technical combined, and last is another behavioral if you make it past the last stage.

The entire process was professional and what you expected but when it came to the final interview they were late and took forever to respond. The technical question was not bad.

It is an extremely drawn out waste of time. You will first interview with the overly excited recruiter that talks everything up, followed by the mid-level developers who ask you some surface level questions about programming. Next, everything falls apart. You will be interviewed by senior management/directors and will be asked a series of basically irrelevant, open ended questions. They will catch you off guard, and you will probably feel uncomfortable trying to create an oral presentation on the fly. You will get little in terms of response or reaction when answering, which only makes the experience worse. It feels more like an interrogation than an interview and feels like it was designed to be this way to watch you squirm around and feel stupid. In my experience, sometimes they weren't even listening, and they were staring at other things during the interview. It was a little unprofessional, but I suppose this doesn't matter to them. If you have anxiety, don't even bother. For a software company, they clearly don't understand how a lot of developers operate. Making people feel uncomfortable is the worst possible way to conduct an interview. You'll also be waiting 1-2 weeks for a reply either way. Ruined the rest of my day and made me stress eat.