10.18Polling

Another common pattern:

Scheduler
   ↓
every 15 minutes
   ↓
query Salesforce
   ↓
find changes

Example:

Scheduler
  ↓
SELECT records
WHERE LastModifiedDate > watermark

This is polling.

Pros:

simple
works when source has no event mechanism
easy to reason about

Cons:

delay
repeated queries
API consumption
watermark complexity
deleted-record handling