Welcome to your interview.
The question is on your right: Real-Time Collaborative Course Editor. 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 the backend architecture for a real-time collaborative document editor where multiple users can edit a learning course simultaneously at 360Learning?