Hi @Marco_Vastolo, I’m one of the developers of MongoSwift.
The Swift driver would be useful if you’d like to write a traditional backend application in Swift. This might be useful if, for example, you’d like your iOS app to send requests to an HTTP server which handles database interaction. From your backend you can use MongoSwift to connect to a MongoDB deployment.
You could use a web framework such as Vapor to implement the HTTP server. We have an example project available here that uses the driver with Vapor which you could use as a template for writing such a backend.
That said, given you are building an iOS app I agree it is worth exploring what Realm supports as well to figure out what best suits your use case.