What to expect in interviews/how to prep for HF

I am a trader at a prop shop looking for advice on what to prepare for interviews. Obviously I am really connected with the markets and the strategies we use to generate money. My question is for example a shop like Citadel, how do I prepare for the online assestments, etc. Modeling? I never modeled before, but I understand how it works. We just model in our heads on the trading floor, any good resources, advice. Thank you!!