This is so weird. If you're using this library

1) your serverless and edge runtime needs to have internet access, so it can contact anyone

2) you're obviously not going to be able to efficiently write to S3 while providing guarantees, so it'll be expensive

3) you're writing in rust, so you really care about correctness and efficiency

This seems like a contradiction. Why would you do this as opposed to hosting a redundant postgres on 2 Hetzner/OVH/... servers and writing to that?