Applied online after meeting a recruiter at my university. Heard back a month later and completed some basic intelligence and personality tests (LSAT and Meyers-Briggs type questions). Also sent in a more detailed explanation of my qualifications, particularly related to foreign travel. Phone interview was a month later, then after another month I had an in-person interview. Both were very straightforward and focused on my writing, research, analytical, and teamwork background in a lot of detail. My advice to candidates who get this far would be to stay on your toes, up to date on current events, and know your resume cold as you will be grilled on it. Overall impression of the interview was that it was extremely thorough but also exhausting. Heard back within a month with an offer and then began the security clearance process, which is a whole different saga. If you are fortunate enough to get an offer, make other plans because you won't start for a long time. Apply, then forget about it until the next step comes along.