Applied through a referral from the company. Great experience - cool people, stimulating interviews, and very efficient HR.

Two coding questions were on the phone interview: one on adding integers of arbitrary size and another that I can't recall.

On-site interviews entailed 5 back-to-back interviews and lunch.

1. Talk with a manager and questions regarding TCP Path MTU discovery - black hole connection.
2. Others were whiteboard coding and design questions. Study up on algorithms and data structures!

Phone screen:

The troubleshooting scenarios were typical things I'd seen in my 10 years administering a large network of Linux machines.

For the coding exercise, I chose Perl because that's my best language. As a result, I had to explain some of the code to the interviewer. (I think Google uses mostly Python.)