Automating Multi-Carrier Fulfillment for a Medical Device Distribution Platform

Before changing anything, we reviewed how orders actually moved through the system. We pulled real order data from the WooCommerce database and the ShipStation API, compared it against the site’s order-processing logs, and traced how shipping data is set at each stage, from checkout through to the warehouse’s shipping software.

On the fulfillment side, that surfaced three separate, layered issues, plus one edge case. Only one of them matched the client’s original theory.

1. A genuine mapping-table gap. Orders priced by a real-time carrier-rate plugin arrived with FedEx service names that included a trademark symbol. ShipStation’s saved mapping table stored those names without it, so the exact-match lookup failed. This was the one issue that matched the client’s suspicion, and we corrected it directly in ShipStation’s configuration.
2. A cosmetic symptom with a real cause. Orders billed to a customer’s own FedEx account always showed as unmapped, even though existing automation was setting the correct service and billing account behind the scenes. Checkout was sending ShipStation a static shipping method label that never recorded which FedEx service the customer chose, so it could never match under any configuration. We added logic that appends the selected service at checkout, so ShipStation’s own mapping resolves it.
3. A silent defect in recurring orders. WooCommerce Subscriptions renewal orders store shipping and billing details in a different internal format than a one-time checkout. Neither the checkout fix nor the existing billing automation recognized it, so some renewals were passed over with no shipping account applied. We built a shared resolution layer that reads both formats, used by the checkout fix and the server-side billing automation.
4. Split shipments skipped. When ShipStation split an order into multiple shipments, the billing automation found several matching records and stopped rather than risk billing the wrong one. It now applies the correct service and billing account to every shipment a split order produces.

The wider assessment also found the store running eight overlapping shipping and fulfillment systems. Rather than patch each one, we retired them and replaced them with a single system, then worked through the remaining findings by severity, from critical security and checkout issues down to logging, caching, and configuration cleanup.