Welcome to your interview.
The question is on your right: A/B Test for Trading Workflow. Take a moment with it first.
Talk your thinking through with me if you like - when you're confident, submit your answer and I'll grade it like a real screen (7/10 or better passes). Discussion and graded submissions share your five interviewer interactions, so spend them well.
You work on a trading product where the team has developed a new signal or a workflow change intended to improve trader decision-making and execution quality. Because changes in trading behavior can affect both performance and risk, you want to evaluate the change carefully before rolling it out more broadly.
How would you design and analyze an A/B test for this new trading signal or workflow change? Walk through the hypothesis, metrics, randomization approach, sample size logic, and how you would decide whether to ship.