An event is a data record that can be serialized and transmitted using the messaging platform of choice. A typical event schema includes the event’s metadata and its pay‐ load—the information communicated by the event:

{

"type": "delivery-confirmed",

"event-id": "14101928-4d79-4da6-9486-dbc4837bc612", "correlation-id": "08011958-6066-4815-8dbe-dee6d9e5ebac", "delivery-id": "05011927-a328-4860-a106-737b2929db4e", "timestamp": 1615718833,

"payload": {

"confirmed-by": "17bc9223-bdd6-4382-954d-f1410fd286bd",

"delivery-time": 1615701406

}

}

An event’s payload not only describes the information conveyed by the event, but also defines the event’s type. Let’s discuss the three types of events in detail and how they differ from one another.