All the apps we've built so far were typical web applications with a frontend UI (accessible through a browser) and a server (backend) that serves the data and the UI content to a user, and the user interacts with the UI and sends data back to the server. That was pretty much the workflow so far.In this chapter, we will build something different. We will add another communication layer to our stack, called gRPC, and we'll explore another scenario where we have machines exchanging data with other machines over the network without human assistance.Internet of Things or IoT has become a buzzword recently due to the growth of devices connected to the Internet. Nowadays, there's nothing new in having a fridge, a doorbell, a thermostat, all connected to the network controlling the energy settings or security of your house. Today, almost every major car company invests heavily in the development of autonomous (self-driving) vehicles, and startups are popping up every day with all kinds...