14-15 rounds of interviews seem to be the norm. you get through 4-5 interviews with the senior management and then they do a status check before you meet the functional team heads and HR. Final 2 candidates are sent to the HQ to meet one of the founders.

It was pretty exhaustive - phone based plus in person in Sydney and SF. Good use of technology, very adaptable to time differences and access to senior people. The check-in process once you have been hired is first class.