The first interview was called the Code + XP/Stats Case Study and started with stats questions in the Signal code framework. The question was a two-dice game where you get $1.1 when you roll a dice and get a strictly higher result and lose $1 otherwise. The second question is you roll a dice 3 times and compare your highest with the opponent, with the same payments. The third question was, you throw N dice and the opponent M dice, then you compare the highest min(N, M).
Then there was a case study on why batching food orders might be reasonable, what metric to build, and what experiment to design to estimate the effect of batching.