I'm still in the interview process and will update this as I go and finish.
I applied online on the Blue Origin website. I was contacted about a week later for an initial HR phone screening, which lasted about 30 minutes. It was non-technical. She was a little late to the interview, but was super nice and informative during the phone interview.
I was then passed onto the next round, which was interviewing with the engineering manager of the team that I the job was for. The technical interview lasted about an hour. The interview was not structured in terms of questions; it was just questions that were thrown at me when I talked about my projects. It was technical because he wanted to know about my thought process. So it wasn't just this is what I did and the results, but a lot more of "why I did it, how I did it, and then results". So definitely review your projects and know them in detail. He said to wait for my HR person to contact me to tell me whether or not I moved on in the interview process. Overall, the process has been pretty efficient.