I applied through university. The process took 3 weeks. I interviewed at MITRE (Bedford, MA) in Dec 2018
Interview
Started out with a phone screen that was about 30-45 minutes. Mostly just asking about experience and talking about the group that I applied to. Then had a second phone call with the head of the focus area within the group. This was mostly behavioral as well. Went in to give a 45 minute technical presentation about my MS thesis and be a part of 6 or so interview sessions, 30-45 min each. I flubbed some of my responses to these which is likely a big part of I didn't get an offer. Throughout the process people were pretty cordial. They provided lunch.
Interview questions [1]
Question 1
A sample signal detection problem was provided, after which you design a block-level system to do so. Followup questions depend on how you approach it initially.