CV application, phone call and then a formal interview. Google is a prestigious company so make sure you know your stuff! The process is tough and the interviewers want to know about your experience in the field.
I applied online. I interviewed at Google (Singapur) in Mar 2015
Interview
Started with a phone interview. In the phone interview first I was asked a bout my previous UX experiences and then at the end a design scenario was described and I had to explain how would I handle it.
I applied online. The process took 3 weeks. I interviewed at Google (Seattle, WA) in Feb 2016
Interview
Straightforward process - hiring managers were very helpful and clear about what I needed to do. They responded in a timely manner if I had a question about the interview or interview process. After I was not offered a position, I was still able to contact the hiring manager and meet up with them for a follow up on what else I could improve on for the next time that I apply.