The game itself is not complex at all -a simple board game. But complexity comes from the fact that when 1 player makes a move, the opponent must get this information immediately.
Obviously this is the responsibility of the backend. I plan to use Firebase for this purpose, but I am not sure if Firebase is capable to pass thru tons of messages like this. And I know it has cons because it's cheap and mBaaS cloud service.
Reading the docs did not tell me much - only bragging how they can do this all.
Does anyone have personal experience with Firebase and real-time game that exchanges a lot of messages between 2 players? Do I need any special setup in the code?
Yes it is definitely suitable. I build a game for iOS using firebase as backend and it is capable handling that messages. You don't need any special setup just include the sdk and configure Firebase in your Appdelegate class and voila start using your real time database.
Short description: Firebase is a cloud hosted Realtime Database. The data is stored as JSON and synchronized in realtime to every connected client. When you build cross-platform apps with our iOS, Android, and JavaScript SDKs, all of your clients share one Realtime Database instance and automatically receive updates with the newest data[Description from Firebase].