[ethangunderson]

The idea should be that you are picking the right tool for the job. Just because you could just use Postgres, doesn't mean that another data store wouldn't be better suited for your problem space. Could be Mongo, could be Cassandra, it very well could be Postgres, but you should be doing some up front analysis and research before you make that decision.

[code_duck]

Sure. My point is that as far as I can tell, Postgres would be better suited to the application, but they want to use Mongo because it's new, regardless of the fact that data integrity, not sheer performance, is more important for this application.