Interview with HR, then hiring manager individually, followed by a day of panel interviews with the engineering team you'll be joining. One or two people per panel for 30min each, several panels.

Straightforward round robin 3 people. We sat in a conference room, discussed some of my previous positions and design experiences, they trumpeted how great their company was blah blah. Eventually we had a simple design scenario wherein they tried to put me on the spot, I solved their problem the manages asked everyone else to leave and he asked me how much.