Welcome to your interview.
The question is on your right: Indexing and Performance Tradeoffs. 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 does database indexing work under the hood, and how does it impact read versus write performance?