Overall, drawn out and terrible. It was the interview equivalent of "breadcrumbing" and a waste of time.
I started the interview process in early March, and had a phone screen, and then a 2 hour technical interview. Hiring was paused, but months later in August I received an opportunity to apply again.
But they required me to go through both the 2 hour technical interview, a 1 hour interview with the hiring manager, and then a 1 hour panel session grilling me for culture fit. I asked to speak with engineers my level to get a feel for the company, and was instead, interviewed and asked additional technical and behavioural questions. I was prepared for a general 30 minute phone call with a potential coworker, not another formal interview.
6 weeks after the second round, there has been little word back. After approximately 8+ hours of interviews, scheduled during my workday, I would have expected slightly more courtesy. This was not a good process, and I'm upset that I spent so much emotional energy and time.