Screener call followed by take home design challenge and a thorough portfolio review with a design team. That interview about your portfolio is about 1-2 hours long and be prepared to answer many many questions.
Multi stage - went through an interview stage, then a deliverable - was recommended by someone else at google. Got positive feedback from the interview - didn't make it past the deliverable round
Interview questions [1]
Question 1
Asked about approach to design, why I want to work at google
Very smooth interview with no pressure. Interviewer was friendly and helpful to me. It was one the easiest interviews I ever had. It lasted about 20 minutes and the experience was awesome.