I was contacted by an internal recruiter who thought I was a good fit for the position. After speaking about the job and agreeing on our mutual interest, we had a quick phone interview. The recruiter then determined I would be a good candidate and asked that I have a phone interview with the hiring manager a few days later. The interview went fairly well. I knew the answers to most of the technical questions. If the manager liked my response, he always asked a followup question that was more in depth or that expanded on my answer. He assured me that it didn't matter if I knew the answer and that he was just trying to get a feel for what I knew.