Welcome to your interview.
The question is on your right: Design a Real-Time Chat Ranker. 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.
You are designing the ML system for a real-time chat application. The product needs to surface the most relevant conversations and message suggestions while keeping responses fast and fresh as users send messages continuously.
How would you implement a real-time chat application?