The sensor interface requires the server application to obtain readings from it periodically. Since physical objects are the only thing we cannot actually convert into software, this will have to stay on-premise.

We could move the application server to the cloud and use Firebase's cloud lambda functions to execute the same code that is currently being executed on the Pi, but then we would need to create another server on our Pi that exists just to fetch and server information from our sensor.

Since the core functionality of our application server is precisely this, it does not make sense to move the server to the cloud. In short, we need some kind of server on the Pi to fetch and send data.

We can, however, transform the server into a process and remove the APIs since we will no longer be needing them. Our APIs, then, which were previously used to retrieve the data on database, will move to the APIs that the Firebase Realtime Database provides out of the box

In the end, our modified architecture will utilize the best of both worlds: