[emidln]

It's really not hard to pick a natural key to use for idempotency in your persistence layer. If you don't want at least once delivery, why are you picking SQS instead of some random ephemeral queue like NATS?

I second the parent post. I've billions of messages through SQS at a previous job and I can remember having issues with SQS availability exactly once (due to a systemic failure involving DyanmoDB where cascading failures took down almost everything (and all of our integrations) that would have hosed us completely if not for our durable-queue/s3-journal[0] at the edge). SQS is simple to use, does what it says, and has very good SDK support. A++++ Would build a business on top of again!

[0] https://github.com/Factual/s3-journal