> No longer do you need to provision server resources, or deploy API endpoints in the cloud, or manage a database
So you don't manage a database, but what happens to the data.
Can anyone trace an example, I don't, order or cart update from client code to persisting it on the back-end somehow? Does it use flat files...?
It's just a higher level of abstraction, not a new technology. And certainly not flat files.
* http://blogs.enterprisedb.com/2014/09/24/postgres-outperform...
That said: There's nothing intrinsic in meteor that ties it to Mongo. No reason why, say, a Postgres or Memcache or whatever backend couldn't exist.
B: It is possible, perhaps even common, to write apps without server side storage at all - imagine API frontends or data aggregators.
Currently it uses MongoDB, though (last I heard) there are plans for Postgres and possibly more, but it will have to work like MiniMongo on the client (i.e., no ORM, and mostly the same on server and client).
It's pretty much hassle-free though, especially with some of the community packages, such as collection2 and simple-schema.