The interviewing group (myself and 3 SEP employees) I was with seemed very disinterested and honestly bored with me. Be prepared to ask them a lot of questions and lead the interview yourself -- they hardly asked me anything about my experience / skills / interests. Ah, and don't be alarmed if one of them literally FALLS ASLEEP while you are showing them a project you're proud of. Totally normal behavior.
You spend the majority of the day at their office ~9am - 3pm
You get a full tour of their office, do a couple whiteboard problems, go to lunch with a few team members, and then finish by "teaching" them something or showing a project or some code you've written.
I felt pretty uncomfortable for a lot of the interview process. It really felt like they were going through the motions and had no interest in vetting me for the job opening. One person was on their phone during the interview, and like I mentioned earlier, another was falling in and out of sleep, even snoring at one point. Not even joking. I felt so embarrassed and wanted to walk out.