Referred by Google employee; completed online coding test, and then had two phone screens. The questions were hard, but honestly, not impossible and very doable overall. I highly recommend scheduling your Google interview after some other interviews so you have practice. If I had scheduled mine just a few weeks later, when I had already faced similar interviews at many other companies, I'm confident I would've passed the interview. The questions weren't out-of-this-world difficult. I heard that I was rejected about two weeks after my interviews.