Real Time Data Processing and Consistency Questions

Covers architectures and trade offs for low latency real time processing and the consistency constraints that accompany them. Candidates should describe streaming ingestion pipelines stateful stream processors message queues and event driven architectures. Discuss ordering and delivery semantics idempotence deduplication and approaches for exactly once or at least once delivery, batching and back pressure strategies, the role of caches and materialized views in reducing latency, and how to reason about correctness versus freshness in a real time system.