Amazon Software Engineer interview questions

A friend sent in my resume. I had a phone interview within the week. It was a one-hour interview with a software engineer on the team I was applying for. The first question was, "Tell me about an interesting book you read recently." Then we discussed my past experience (I described my master's thesis research), and then we moved on to coding questions. Finally we discussed the position and working at Amazon in general.

Got a call from company's recruiter and have a phone interview. The recruiter is very proactive since I originally only get an email and I did not respond to it. Then a week or two later the recruiter called me. The phone interview is long (around 1hr 15min) The interviewer did not ask many questions on my job but instead ask me several technical questions. The interviewer is fair but he did not volunteer any hints.