First step is a phone interview where they are primarily checking you for cultural fit. If you are a concerned humanitarian, you're in. Second step is a video interview concerned with overall technical ability at a high level. Third is an in-house interview where you will need to prove you know what you are talking about. Depending on your demeanor, they may want an additional phone conversation. My advice is to be humble, ask questions such that you arrive at the desired solution in conjunction with the interviewer. They actually want confident self starters, but being overly confident will get you further scrutiny.