Welcome to your interview.
The question is on your right: Infinite Scroll for Large Video Grid. 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 build an infinite scroll UI for a grid of 100,000 YouTube videos where the browser dimensions are undefined?