> no direct reads of another team’s data store This reminds me of how App Store used to ban game emulators interpreting ROMs downloaded from the internet, while at the same time allowing XML parsing. Does it really matter if the interface you're talking to over the network is code written by another team, or data written by another team? I suppose implementation details are often hidden away in data stores, but does…
This pretty much freezes the database schema, the team owning it can no longer change it, because they don't know how the users use it. It also limits the possibilities to provide optimizations on the data (like caching).