When proposing Platform Events as an integration mechanism, an architect must ensure that the security model is correctly configured to allow for the publication and subscription of events. Unlike standard objects, Platform Events have specific permission requirements for the "Integration User" or any system entity interacting with the event bus.
For an external system to subscribe to a Platform Event stream (via CometD or the Pub/Sub API), the user account used to authenticate the connection must have the "Read" permission on the specific Platform Event entity. Similarly, if the external system needs to publish events back into Salesforce, the user must have " Create" permissions. These permissions are typically managed through a Profile or a Permission Set assigned to the Integration User.
Regarding the other options, Option A is incorrect because Platform Events are designed for asynchronous communication. They are inherently decoupled; the external system does not need the same uptime as Salesforce. High-volume platform events are stored in the event bus for 72 hours, allowing an external system to "catch up" using a Replay ID once it comes back online. Option C is also incorrect because Platform Events follow a Publish/Subscribe pattern. Salesforce "broadcasts" the event to the bus without needing to know which specific external systems are listening. This decoupling is a primary advantage of event-driven architecture, as it allows for a "one-to-many" distribution model where multiple systems can consume the same message without additional configuration within Salesforce. Thus, ensuring the correct object-level permissions (Read/Create) is the most critical technical consideration for the architect to guarantee successful message delivery.