I have gotten a conversation working between the web client and the android app relying entirely on firebase for notifications. Yay! Except both ends only work in the production environment. So development is slow, because my deployment process is slow.
It also raises a philosophical question of when to fall back to another technology. How would I be able to tell the difference between firebase not working, and just not getting any messages? There is no way, because I can’t confirm something that isn’t happening. So every once in a while, it may be necessary to poll the server anyway, just to see if firebase is working. Granted, firebase will probably be working 99.99% of the time, so it may not even be worth checking. But I might just throw it in there for good measure. Maybe only if the app/webpage is active for some long amount of time with no messages received.