I am planning on developing a social media app but have no idea what database to use. I have been learning to develop android apps and the databases that I have used so far are only SQLite and Firebase Realtime Database. I understand that SQLite is a local database and not the right database for a social media app. Firebase Realtime Database, on the other hand, can be used to build a social media app but I have heard that some problems may occur if Firebase Realtime Database handles a lot of users.
I have been thinking about MongoDB as from what I heard, it can handle millions of users. There are things like MongoDB Stitch, I am planning to use that one but I wonder if it is the right database to use for such an app? or is there any better database?