Apologies, I misspoke. SQS does have a FIFO+Exactly Once Processing mode, so it will never introduce duplicate messages into the queue. It of course doesn't hav

Apologies, I misspoke. SQS does have a FIFO+Exactly Once Processing mode, so it will never introduce duplicate messages into the queue. It of course doesn't have exactly once delivery without additional state tracking on the consumer outside of the queue.