Firstly, I have to say, there's no need to be nervous nor get too much into prep - the more natural you are the better. Just make sure you know WHY you applied, WHAT is the industry the company operates in, and have a slight IDEA of the job position; but more importantly, ask if you do not know the answer. I got to meet both the team leader and one team member at the very first interview, who gave me limitless time to ask and get to really know the position & reward model. The second interview couple days later was conducted by a CEO, with whom I had a practice call (better not be perfect just natural, because there's no need to be perfect at this interview stage) and then again, I had enough time for Q&A.