Backplane interview questions

I had three phone interviews before flying to Palo Alto for an in-person interview. The phone interviews were all about 30-45 minutes long, and consisted of technical programming questions. Two of them gave me a "homework" problem at the end to code and send back to them. The In-person interview was a little more intense, and lasted about 6 hours (including a free lunch). I spoke with 6 different people, and each one consisted of technical programming questions, similar to the phone interviews.