I applied online in September 2014. I got an e-mail 3 days later asking to set up a phone screen. I had an initial half-hour call with the two recruiters, reviewing my background and interest in the position. After a three week period, I finally heard back from the recruiters, inviting me for an in-person interview. I met the two recruiters at the HQ in Alexandria a week later. After another two week stretch, I was invited for a third round to meet with some hiring managers in the company. It was a panel interview, consisting of 7 members of their hiring team, split into 30-minute sections. After that interview, I waited another two weeks until I heard that I didn't get the job. The entire process took about 2.5 months
The recruiters were very up-front with me that the process would take a while (typically, they invite candidates back for several rounds of interviews and it can take several months). All of the people I met with were pleasant, intelligent, and seemed to love their jobs and the company. It seems like an excellent place to work.
There were a few negative aspects to the process that I think could be improved. The recruiters always gave me a date by which they would call/e-mail me with any updates, and never met that deadline. All feedback/scheduling communication was done by e-mail, so it was hard to get in touch for updates. At the end of the process, when I finally heard back that I didn't receive the job, I received a standard rejection via e-mail. This was after three rounds of interviews (two were in-person), and I would have appreciated a call informing me of the rejection.