You can write a DDP backend which is backed by Postgres. In such a case it ought to feel like Mongo is just serving materialized views of the genuine, consisten

You can write a DDP backend which is backed by Postgres. In such a case it ought to feel like Mongo is just serving materialized views of the genuine, consistent data. If you treat the Minimongo data that way—just consistent enough to show an image once—and verify all the writes on the server then you ought to be able to get by.