Connected to what you already run

Sync is the easy half

Any competent engineer can call an API and write the results somewhere. What fails, months later and quietly, is everything around it: an API version deprecates, a webhook is missed during a deploy, somebody edits a record directly in the source, a retry double-writes, a field that was always populated starts arriving null.

None of those raise an error. They produce a slow divergence that surfaces at close, when somebody notices that the number here does not match the number there and nobody can say when it started.

Reconciled daily

Every connector runs a daily reconciliation independent of the sync itself: counts, control totals, and spot-checked records compared between source and graph. A mismatch raises an alert with the records attached rather than waiting to be discovered.

That check is deliberately not built from the same code as the sync. A reconciliation that shares its assumptions with the process it is checking will confirm those assumptions rather than test them.

Idempotency, because retries happen

Every write carries an idempotency key derived from the source record and its version, so a retried delivery updates rather than duplicates. Duplicate transactions from a retried webhook are one of the most common integration defects we are called in to clean up, and they are tedious to unwind after the fact because the duplicates are individually valid.

Where it is honestly harder

QuickBooks Desktop has no cloud API. Extraction runs through the SDK against a company file on a machine somebody maintains, and it is roughly three times the elapsed work of the online edition — which is why we quote it separately rather than pretending the two are the same job.

Older on-premise systems and anything reached through a database read replica or a nightly file drop are scoped case by case. We will say in the first conversation which of those yours is, because discovering it in week six is how integration projects go over.