Your consumer retried a bad message 10,000 times. It will never succeed. Dead letter queues catch the messages that can’t be processed so the rest of your system keeps moving.

What happens to in-flight requests when you deploy? How to shut down cleanly without dropping connections or corrupting state.

Why setting timeouts is harder than it looks. Cascading failures, timeout budgets, and the art of picking the right number.

How circuit breakers prevent cascading failures in microservices. State transitions, Java implementation with Resilience4j, and real-world thresholds.