Responses have ranged from, your doing it wrong to “no”

At one point we had a dozen different Amazon accounts to keep everything separate. Thankfully the business model was crap, so if resolved itself.

Self-destructing business model is the most effective scalability strategy for developers by far. Just make sure you do net 30.

LoL, for the way you finished your point. Good to know your experience :)

Did Amazon mere said, "you are doing it wrong", without an explanation? In retrospective, do you think you could have done better? I'm looking to hear the lessons you learned, so may be, I don't end up making that mistake ;)

For dynamodb it was “you need to rethink your data structure”

S3, I think they did up the bucket limit on request, but maxed out at 1,000. That was years ago though.

I guess the way they want you to do it in S3 is using a per tenant key prefix with security policy set? AWS roles and security policies are quite flexible so I guess in theory you would get the desired isolation that way. Separate buckets are still easier, though...