AZ-305 · Question 43 · Domain 4.2: Design an application architecture

You are designing an event-driven architecture for an e-commerce platform.

When a customer places an order, an 'OrderPlaced' message must be generated. This message must be processed by three independent downstream systems: Inventory, Billing, and Shipping.

Requirements:

• Each downstream system must receive its own copy of the message.
• If a downstream system is temporarily offline, its messages must be retained until it comes back online.
• Messages must be processed in the exact order they were received (First-In-First-Out).
• The system must support transactional processing (if Billing fails, the message goes to a Dead Letter Queue).

Which messaging service should you recommend?