Your question is Threaded Messaging System Design. Take a moment with it on the right.
Talk me through your thinking if you like. When you're confident, submit your answer and I'll grade it like a real screen (7/10 or better passes).
Design and implement a threaded messaging system where a dog owner can contact a dog sitter and a Rover agent can also be involved. Clarify the message, thread, participant, delivery, and authorization APIs, then describe how ML could classify conversations and route agent involvement. Explain storage, consistency, notifications, observability, and failure handling. Treat the system as a practical production design and call out assumptions that must be confirmed before capacity planning.
