It's really hard to have exactly-once delivery[1]. But exactly once processing is viable. With Differential, the implementation does allow for idempotency in

It's really hard to have exactly-once delivery[1]. But exactly once processing is viable. With Differential, the implementation does allow for idempotency in cases where you need exactly-once processing. And it does handle the "not available, but already 'stolen' case". Disclaimer: I'm an author. [1] https://news.ycombinator.com/item?id=34986691 https://news.ycombinator.com/item?id=34986691