Usually half day, one on one process with 6-8 managers / senior engineers. More experienced engineers typically have to give a presentation in addition to one on one interviews. Typical situation questions, name a time when etc. They are interested in people who will fit in with others in the company and who fit the culture more than the smartest candidate with the most degrees. Being young and attractive seems helpful. Be confident but not a "d-bag" word used to describe a candidate once :)

Multiple stages from HR, hiring managers, peers and other levels of management spanning several weeks. Peer interviews was an interesting addition helping to get insight into how the team and company works at an individual contributor level.