You have decided to adopt an event-driven architecture, modeled your events, and decided what style of event you will expose. One of the aspects that I recommended was for you to add to the events the version of the entity after it mutated. Event-driven architecture is a powerful approach that touts the scalability and decoupling of the systems involved. Common issues with events can be seen below: Losing a message, Out-of-order messages, Duplicate messages. Having a version attached to the event can help in both cases.
