Welcome to your interview.
The question is on your right: Join Performance and Window Function. 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.
Explain the performance difference between an inner join and a left join when working with large-scale datasets, and write a query demonstrating a window function.