Start with one direction of data flow—either inbound or outbound—not both at once. Prove correctness on a small slice: one product family, one branch, one day of sales.
Write down which system is the system of record for SKU, price, stock, and customer identity. If that answer is “both,” you are not ready; pick a winner per entity.
Rotate credentials deliberately, not only when something leaks. Keep a human-readable runbook: who approved the mapping, what fields map, and how to disable the connector quickly.
BillDiary exposes integration APIs and developer tooling so technical teams can onboard without guesswork—while operators keep working in the same workspace.