An order is placed, and it should actually get fulfilled, not just recorded as paid.
"Every order gets fulfilled." Payment succeeding isn't the same as fulfilment happening. An order can be charged perfectly and still never make it into a warehouse or shipping queue if a step in between drops it.
Use the order number as the reference, since almost every platform already has one, and it never repeats.
An order is placed, a matching fulfilment record appears within the expected window (which might reasonably be longer here than for a lead, since fulfilment often isn't instant, and the window should reflect that).
An order is placed and paid, but no fulfilment record ever appears. A sync between the store and the fulfilment system broke, or an automation step silently failed on an edge case (an unusual address format, a product no longer in the catalog). FlowProofs confirms the gap and alerts with the specific order number, instead of a customer finding out first.
Common variant