I applied online, but then had my resume passed on through a mutual connection. A couple weeks later I got an email from HR saying I was invited to do an on-site interview with two groups. When I got to the lab for the interview, I first met with a women in HR to go over general information and benefits. Then I took a shuttle to another office building to meet with the first group. I met with various members of the group, from younger employees to the group supervisor. Most of the interviews were a mix of informational and behavioral. They asked me to talk about things on my resume, and why I was interested in working at the lab. They also spent a lot of time telling me about what their group does, and possible projects they might want me working on. I also ate lunch with a member of this group in a small cafeteria located in the building. The second group was back on the main campus. I met with the group supervisor, and then two other members of the group. Most of these interviews consisted of the members explaining what their group does, since they work in a field that I wasn't familiar with. I interviewed on a Friday, and the next Monday I got a call from HR to discuss how the interview went, and she asked me how I felt about the two groups I interviewed with. Two weeks later I got a call saying the group I preferred had given me an offer. The whole process was very enjoyable. Everyone I met was nice and helpful, and there were no hard technical questions. I got a sense that APL is a great place to work. I also think that if you get offered an on-site interview, it means they are impressed with your background and are pretty seriously considering hiring you. So don't stress about the interview!