Interviewed May 2020. Process took 3 months from when I submitted my application to final notice that I was not selected, 2 weeks from when I was first contacted by a recruiter to final notice.
A phone screen with a security officer (job required ability to receive a security clearance), then a friendly phone interview with the hiring manager. After this, a video call was set up to act in place of an in-person interview.
Interview questions ranged from the typical HR questions along the lines of "how do you handle failure" and "where do you see your career going" to personal questions judging team fit and more technical, science and engineering questions. Technical questions felt more like an oral exam from my school days.
Not many of the technical questions were directly related to the job itself. More often than not, they were prefaced with "this has nothing to do with the job, but..." Despite that, based on a short email exchange I had with the hiring manager after receiving word that I was not selected for the role it appears that I was judged almost entirely based on my responses to these unrelated, significantly more difficult questions that included quantum mechanical equations, geometry based riddles, and being asked to give the specifics of cutting edge optical research setups.