First round interview was a phone interview with a Google PM, he asked a few design questions, very broad and not so difficult. I think it was more to get a feel for how creative you can be. The interview was really short, probably less than 40 minutes. I didn't expect a call back. Surprised when I did hear back 2 weeks later with an invitation to on campus interview. They flew a bunch of us in and even arranged a scavenger hunt for us around SF. The actual interview day was long, and consisted of 4-5 one on one interviews with existing APMs. Each of them are responsible for one "area", such as technical, design or both. The design questions often have to do with how to improve an existing product or how to design a consumer product from scratch. Since Google is a web-based company all the designs had to do with websites or mobile apps. Overall, there wasn't any too difficult, but it's hard to think on the spot sometimes. The culture is great, you can tell everyone is super smart there and you'd be able to extract a lot out of the experience.