I have never heard strong consistency used to describe such a weak guarantee before - i.e. it's marketing bs. Usually strong consistency refers to linearizability (or at the least sequential consistency). The diagram a few pages in to this paper gives a nice overview: https://arxiv.org/abs/1512.00168
Yes I actually read that paper while I was digging around but it didn’t seem to help in this case because Amazon don’t specify whether reads made after a concurrent write is made are guaranteed to return the same value as each other. If they are I think the system would be linearizable, yes? Either way they don’t say linearizable anywhere and they describe it specifically as “read-after-write” so I think it would be wrong to assume linearizability. What’s missing from this model for linearizability? S3 doesn’t have transactions after all.
