Employee referral, which a couple weeks later got me a phone interview. A week later I was asked to come down for an in person interview, which consisted of four 30-minute one-on-one interviews and a 1.5 hour lunch. Questions were largely about my experience, why I wanted to work at ICF, what my career goals are. A few behavioral "explain a time when you learned ____" were thrown in the mix. Overall, it was conversational and pleasant.