Real Time Communication Architecture Questions

This topic focuses on design patterns and infrastructure for real time features. Candidates should compare and justify choices between Websocket based connections, server sent events, and polling, and describe the operational implications of each choice such as connection lifetime, server resource usage, and request patterns. At scale, discuss load balancing strategies, connection routing and state, sticky sessions versus stateless approaches, message brokers, and horizontal scaling. Demonstrate understanding of real time features like presence, live updates, and collaborative editing, and design patterns including broadcast, unicast, and multicast messaging. Address reliability concerns such as message ordering, duplicate delivery versus exactly once semantics, idempotency, persistence, and conflict resolution in collaborative scenarios. Be prepared to mention relevant libraries and protocols and to describe trade offs between flexibility, complexity, and operational cost.