I was contacted by a recruiter about a month after applying for the position. We set up a time and did a quick phone screening interview. About a week or so later, I was invited to the Arlington HQ for an in-person interview. I met with two members of the IT team in two one-on-one sessions, and I was asked a variety of questions about my work history, how I got into IT, why I was interested in APT, and a number of technical questions.
A few days later I was invited back for a second interview, and the following week I visited once again for four one-on-one interview sessions (with 3 IT team members and a VP of operations) and an hour lunch with another member of the IT team. It was a long process and some questions were asked multiple times, but they often had different spins on scenarios or tech questions, so it was still engaging and not overly repetitious. They also asked me about my experience working in Japan and studying Japanese (they have an office in Tokyo, so I played that up), so of course be prepared to talk about anything on your resume.
Among the tech questions, I was asked to name different types of hardware I would find in a laptop; how to address storage solutions for a machine, and when one of my possible answers was to replace the hard drive, I was asked how I would go about doing that; how to approach helping a user with a failed internet connection; some networking material like the OSI layers and the differences between a hub, switch, and router. I also had a line of questions relating to IPv4 addresses and CIDR notation. And in my final session I had one of those brain teasers designed to see how you break down a problem - I was given a scenario in which the mayor of DC wanted to fix all the potholes in the city and told that I was to make a bid as a contractor.
Although I had a few stumbled where I wasn't able to answer parts of questions (like I forgot 2 layers of the OSI model), I think I generally was able to answer all the questions well. But I also spent several hours preparing for the interviews, so I'd recommend the same.
Ultimately I did not receive an offer. I was told that I did well but that they decided to go with someone who had experience with large networks. So I guess the wisdom I have to pass on is: have a look at the types of questions they ask, prepare as best you can, try to make a good impression, and cross your fingers.
I was pretty disappointed to be passed over, as it seems like an awesome place to work. The culture is young and fast-paced, it's growing, and there's a lot to learn. Everyone was very kind and I felt like they were rooting for me to do well, and I really enjoyed talking to my interviewers and lunch escort. It was a great experience, to the extent that two rounds of interviews without an offer can be considered one. If you're considering applying, I highly recommend giving it a shot.