Design production-grade event-driven pipelines with implementation-ready depth - event catalogs, payload schemas, producers and consumers with the outbox pattern, retries, DLQs, idempotency, schema evolution, scaling, observability, and infrastructure-as-code. Use when adding async processing between services, decoupling producers from consumers, migrating from synchronous to event-driven communication, designing Kafka / Azure Service Bus / AWS SQS-SNS / RabbitMQ / Pub-Sub topologies, or redesigning retry and failure handling for existing events.
