How to handle duplicate events in your code (or, why idempotency is important)
In some situations, your application may receive a webhook for the same event/message multiple times from Postmark. Under normal circumstances, this should be relatively rare, but it is something your webhook processing should be prepared to handle.
Understanding why this can happen is not only important when working with webhooks in Postmark, but more generally useful in dealing with distributed systems. After all, all apps that use APIs are distributed systems, whether they want to be, or not!
Continue reading • Andrew Theken wrote in Engineering
