Inventory is only the visible layer
Matching inventory between a marketplace and a storefront matters, but it is only the most visible outcome. Products, variants, prices, promotions, orders, cancellations and returns belong to the same system.
When one of these areas falls behind, operations make the wrong decision even if inventory looks correct.
Define one owner for every field
Every piece of data needs a primary source. If inventory comes from ERP, content from PIM and pricing from a commercial system, those ownership rules must be explicit.
Allowing two systems to overwrite the same field is not synchronization; it creates a silent conflict.
Failure handling is part of the product
Moving successful records is easy. A resilient integration knows what to do when a transfer fails and shows which order is waiting, why it is waiting and who should act.
Retries, alerts, logs and correction screens are core integration capabilities, not optional support tools.
Measure accuracy before speed
Moving data in seconds is not enough. It must come from the right source, arrive complete and produce the expected result.
A good integration reduces panel checking and lets people manage exceptions instead of carrying data between systems.