10.19Event vs polling

Suppose Salesforce changes Account.

Polling:

Mule:
anything changed?
anything changed?
anything changed?

Event:

Salesforce:
Account changed!
   ↓
Mule

Event-driven is often lower latency and avoids repeated empty queries.

But it adds:

event infrastructure
delivery semantics
replay considerations
ordering issues
consumer state

So polling isn't automatically bad.