Welcome to your interview.
The question is on your right: Deep DOM Performance. 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.
What are the performance implications of deep DOM trees, and how do you mitigate them in a large React UI?