First I applied online by submitting materials like a resume, transcript, and letters of recommendation. Then I got a call to set up an onsite interview. They flew me into Alexandria and had me stay at a hotel that was a short walk away from the office. First I met with HR, then had a technical panel with two researchers. Then I went to lunch to a nearby restaurant with two other researchers. Afterwards, I met with another researcher and then the director of the Data Science Fellowship. The whole thing was about four hours. For the most part everyone there was very friendly and accommodating. My only complaint is that they searched my luggage (as in they literally opened my suitcase and went through everything) right there in the lobby which was extremely awkward.