Event-Driven Architecture Decisions and Delivery Guarantees

Classify a message as a command, event, or document message from its intent and ownership.

Redesign a synchronous microservice interaction as asynchronous messaging and identify the coupling removed.

Define an event contract containing business facts, identity, time, source, and correlation metadata.

Distinguish event notification from event-carried state transfer for a given workflow.

Select at-most-once, at-least-once, or effectively-once processing for a stated business requirement.

Define the required ordering scope for events in a business workflow.

Design an idempotency-key and deduplication strategy for an at-least-once consumer.

Identify consistency, latency, availability, and operability trade-offs in an event-driven design.