Short write‑ups of problems we hit running a real commerce operation and what we changed in the code because of them. No product announcements; just the reasoning.
From the packing bench, one tap books the shipment, prints the label and writes the tracking number onto the delivery note — for eight carrier integrations across four countries, each with its own dialect: SOAP here, REST there, XML that breaks on an ampersand, a service that refuses more than one parcel, cash‑on‑delivery that must go on exactly one box. What the shipment object has in common everywhere, what each carrier taught us, and why every integration ships with a "manual" twin.