As with any government position, it took an amazingly long amount of time between applying for the position and getting called in for an interview. They put me up in a hotel and paid for everything.
On the day of the interview, my contact brought me upstairs and dropped me off with a higher-up for a quick interview. Then I interviewed with my contact and a supervisee. I did this process three more times in three branches (a total of five or six interviews for the day). I had started at 8:00AM and was out by 2:00PM.
All of the interviewers asked very similar questions: coursework, ability to work in groups, statistical computing experience, major projects, and the like.
Somewhere between four and five months later (remember: government) I heard back with a job offer. They paid for the entirety of my move and travel expenses. Other than the amount of time it took to make it through the entire process, it was fairly painless, and the people here are great. They are knowledgeable, helpful, and fun.