I did the design of a project that used Angular inside Ionic with Firebase as backend. They integrated well, no particular problem. Just be careful not to keep websockets open unless those you really need. Close the others. They'll keep the CPU busy and bleed the battery.
The only major problem was with Firebase itself, when we had to start duplicating data because it's a tree and it doesn't have joins. But it would be unfair to complain because it's like that by design and we knew what was expecting us. Is there any service like Firebase but with joins?
I haven't used Firebase, but would RethinkDB with its real-time feature be an alternative that has joins? It has the drawback that it'd be self-hosted, but apart from that..?
The only major problem was with Firebase itself, when we had to start duplicating data because it's a tree and it doesn't have joins. But it would be unfair to complain because it's like that by design and we knew what was expecting us. Is there any service like Firebase but with joins?