Real Time Data and Communication Questions

Covers designing and implementing real time client server communication and data flows. Topics include transport mechanisms such as WebSockets, Server Sent Events, long polling and regular polling with appropriate intervals; connection lifecycle management including reconnection strategies, exponential backoff, and error recovery; data synchronization patterns including optimistic updates, conflict resolution, reconciliation strategies, and eventual consistency; offline first approaches, caching strategies, and state reconciliation when network connectivity is restored. Also includes streaming concerns such as memory management, backpressure, batching and windowing, message ordering and idempotency, sequencing and versioning, and techniques for broadcasting and multicasting data to multiple clients using pub sub or message broker architectures. Considerations for authentication and authorization over realtime channels, scalability and load balancing for persistent connections, monitoring and observability, and trade offs between latency, consistency and throughput are also assessed. Candidates may be asked to design end to end solutions, justify technology choices, and explain implementation details and failure modes.