Sync. The response tells you immediately whether every target accepted
High volume, or a slow downstream (ERP)
Async. Get a job ID back in milliseconds, poll for the result
Backfill or migration
Batch. One request, many orders, per-order results
All three run the same fan-out, so all three can partially succeed — NetSuite accepts while
fulfillment rejects. Whatever endpoint you use, read the per-target results rather than a top-level
success flag.