Decide which system owns each field
Connecting a point-of-sale system to an online store requires more than copying product records. The first decision is ownership. The POS may own the SKU and selling price, while the website owns product photography and marketing descriptions. Without explicit rules, one synchronization can accidentally erase another team’s work.
Use stable identifiers
Product names can change and may not be unique. Store a stable external identifier alongside the local record, and enforce uniqueness within the relevant source or company. Record mappings for variants and locations when the systems model these concepts differently.
Make retries safe
Network requests can time out after the receiving system has already saved the change. Design repeated requests to produce the same business result. An external event identifier or another idempotency key can help prevent duplicate movements and orders.
- Record the last successful synchronization and a useful error message.
- Retry temporary failures with increasing delays.
- Keep invalid records visible for review instead of retrying them forever.
- Do not advance a checkpoint before the corresponding batch is safely processed.
Reconcile periodically
Events and scheduled batches can both miss changes because of outages or configuration mistakes. A reconciliation process compares the agreed fields and highlights differences. Start with a small sample, verify totals and mappings, and increase the volume once the business team has checked the result.
Reliable integration depends on knowing what happened, what failed, and how to recover without creating duplicate business activity.