The interview process was very intense. As I already had a couple of other offers already on the table, APL tried to expedite the interview process, which led to 4 straight days of multiple interviews. Each interview was 1.5-2 hours and through the course of the interview you would meet 3-8 employees within the particular group that you were interviewing for. The interviews usually started with a brief overview of the particular group that you were interviewing for and then they would ask questions on your background / experience and some technical questions as well. Not going to lie, the interviews were really hard compared to others that I've gone on as a newly graduated EE. That being said, many of the interviewers were really supportive, easy to talk to, and didn't make me feel stupid or dumb when I didn't know the specific answer to a tough question.
Also most of the interviewers I met and talked with were really passionate about their job and loved to field and answer questions about their experience. They also seemed genuinely interested in your career ambitions and goals and wanted to make sure that APL was a good fit for you.
Best advice I can give is to review your own resume and projects before the interviews, but try not to stress too much before the big day. Just be honest and be yourself! Also, ask a ton of questions. You'll learn a lot and they love to see someone who is curious and willing to learn. I'd prepare a lengthy list of questions before and take notes during the interview of more questions that you'd like to ask when the time arrives. There will be multiple times throughout the interview where you can ask questions. Additionally, many groups allocate a good portion of the 2 hr interview to a Q/A session.