Example firebase and google app engine integration
The frontend is a very simple static website that can be found at public/index.html. It presents the user with a form that asks for their name and age. Once submitted, the frontend will wait for a result to be calculated by the backend and then update the UI with the message.
The backend is using Goole Cloud Functions and it listens for new entries in the firebase database at /form-submissions/{name}. When the frontend submits the form, this function is triggered which in turn adds a results field which is a string concatenation of the form data that says: "Hello {name} from Google Cloud Functions! Your age has been recorded as {age}."
The backend function can be found at functions/index.js.
A demonstration of this simple firebase application is available here: https://pr-demo.firebaseapp.com/