it depends on what is important to you , use the right for the right task mongodb is new girl on the block , very good for aggregated to queries which is very important for mobile (one time trip o server to get all the data ,once) , if your doing anything JS based ,absolutely use mongo , only case i prefer Sql , if you would perform micro update ,that other endpoint relay , say for keeping track of transaction across several file , sql is very well suited for you, but you do without micro updates propagating everything , mongo is a better choice