Ordering is not guaranteed between different topics for the same resource.
For example, it is possible that an ORDER_UPDATED webhook might be delivered before an ORDER_CREATED webhook. Your system should handle such cases.
The webhook events should be delivered at least once. This means that your endpoint might receive the same event more than once from our system. You can detect duplicate events by comparing the id value of received events data.
Webhook delivery is not always guaranteed. If you require your data to be always consistent, you should therefore implement reconciliation jobs to fetch data from Fourthwall periodically.