Why does my storefront inventory not match my 3PL?

Because they are two systems synced on a delay, and every event between syncs is a divergence. Returns restocked at the warehouse, damages written off, orders picked but not yet marked shipped, and inbound receipts all change one side before the other. The gap is the sync interval multiplied by how much happens inside it.

Shortening the sync interval reduces the symptom without removing the cause. The cause is two systems each holding a version of the same number, which is why the durable fix is one system of record that both the storefront and the warehouse read from.

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