Introduction In distributed systems, failures are inevitable—network partitions, broker crashes, or consumer lag can disrupt data flow. While retries help recover from transient issues, you need stronger guarantees for mission-critical systems. This guide covers three advanced Kafka resilience patterns: Dead-Letter Queues (DLQs) – Handle poison pills and unprocessable messages. Circuit Breakers – Prevent cascading failures when Kafka is unhealthy. Exactly-Once Delivery – Avoid duplicates in financial/transactional systems. Let’s dive in! 1. Dead-Letter Queues (DLQs) in Kafka What is a DLQ? A dedicated Kafka topic where "failed" messages are sent after max retries (e.g., malformed payloads, unrecoverable errors). Why Use DLQs? Isolate bad messages instead of blocking retries. Audit failures for debugging. Reprocess later (e.g., after fixing a bug). Implementation (Spring Kafka) Step 1: Configure a DLQ Topic bash kafka-topics --c...