Dataflow is a fault-tolerant deterministic processing framework, engine, and service, not a messaging queue, so it doesn&#x27;t &quot;do that&quot; by definition.. wrong product :)<p>That said, one may order and dedupe the message stream with Dataflow using message metadata, time windows, watermarks and triggers.<p>PubSub offers at least once delivery semantics.<p>And I agree with your last statement.