For new grads, it is a longer process than the interns. You will have one HR call at the start (~15 mins) to check background, then the first round is with 2 people, usually at least one trader and then someone else that is senior in the company. If both individuals vote "yes" for you, you move forward to the second round. In the second round, you will have 2 more interviews, usually with very senior people in the firm on the trading side (IE US/Global Head of _). While the first round is behavioral, the second round is behavioral mixed with technical. Nothing is too hard and can all be approached if you have maintained slight contact with news over the past 3-5 years and have a very basic understanding of the agricultural markets + their drivers for supply and demand. If you pass the second round, you will have an in-person superday. The superday has 5-8 total interviews, all lasting 45-60 mins. Most of the superday interviews are behavioral, but a few ask case study questions (IE look at numbers for production/import/GDP for these countries - now try and make sense of it.) There is also an online assessment that you will take, I don't really think it can be prepared for unless you've seen very similar questions elsewhere.

Call with HR, then first round of interviews at their office in London (3 rounds with 2 people per round), assessment day which lasted the full day with trading simulations, negotiation exercises and more interviews... Loads of weird questions, many market and technical questions. difficult to prepare for coming from a non commodities background... had found an physical trading interview guide online called physical trading prep which helped a lot in preparing for this