I went through five Interviews / steps and I have talked to nine interviewers in total (Manager, Team, HR Business Partners and HR Director, and various business stakeholders). The process was quite heavy and took a month.

2 stages, meeting HR and key internal customer 1st round and HR only for 2nd. The internal customer drove the interview. As you hire for their business they had the say on whether you are hired or not. Very scripted and structured interview, hard to engage when people are not interacting with you but thats the process! Overall the process was as smooth as possible. Big companies dont make it easy to join and there are lots of buttons to press to get in the door.