Welcome to your interview.
The question is on your right: A/B Test for Email Search. 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.
How would you design an A/B test to evaluate a new email search algorithm at Superhuman? What metrics would you track, and how would you determine sample size?