I am loving Firebase's serverless model of application development, so that server solution is not ideal. But I don't think its possible to solve a different w

I am loving Firebase's serverless model of application development, so that server solution is not ideal. But I don't think its possible to solve a different way. That said, there are smart people who have thought of ways of reducing server burden in ways I never thought possible (like encrypted sessions), so it might be possible ??? How does google analytics stop rogue clients registering hits on the wrong domain? It checks the domain the incoming data is on, right? (cookies?)