Referred by a Google employee, I completed an 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 have passed the interview.

The questions weren't out-of-this-world difficult. I heard that I was rejected about two weeks after my interviews.

Questions on graph searching (think DFS, BFS), tree traversal (think inorder, preorder, postorder), array and string manipulation.