To publish a Platform Event in Salesforce using Apex, first create the event in Setup → Platform Events and define its fields. Salesforce automatically generates an Apex class with a __e suffix.
Publishing an event requires instantiating it and using EventBus.publish(). Multiple events can be published in bulk by inserting them as a list.
Platform Events are asynchronous, immutable, and not subject to DML limits, though standard Apex governor limits still apply. They cannot be updated or deleted once published.
