Your question is Design a Chat System for Crusoe. 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 a group chat system.
Asked in the phone screen system design stage. Only the topic "Group Chat" is visible; additional requirements and scale details were not provided.
Discuss the requirements you would clarify, then design the core architecture for message creation, ordering, persistence, fanout, delivery acknowledgements, offline users, membership changes, and message history. Explain how you would size the system once traffic assumptions are established. If relevant, describe where ML could support moderation or abuse detection without making it a dependency for message delivery. Cover reliability, privacy, observability, and failure recovery.