Online stock is a promise about physical bins. Slippage comes from pick waves, damaged goods, and returns not yet inspected.
Agree on authoritative timestamps: when does an item leave “available”? At pick, pack, or carrier scan?
Design for partial shipments and backorders. Customer comms should reflect operational truth, not best-case JSON.
Give warehouse users readable error surfaces—CSV uploads, adjustment reasons, and audit history reduce midnight Slack.
