[jzelinskie]

Thanks for the response. In my opinion, oso does the best of job of any policy engine at prescribing how input data to their system is fed (and your linked blog demonstrates it well!).

I do think you might have pivoted the conversation, though. My post was purely about federation strategies and policy engines, but you appear to discussing consistency and Zanzibar, which is only tangentially related. Federation and consistency aren't necessarily coupled. Oso also would require a complex scheme for achieving strict serializability, but it instead chooses to trade-off consistency of the centralized data in favor for the local data.