Finite state machines are usually the thing of nightmares for CS undergrads. The first question any CS student asks after seeing them is "But where will I ever use this?". The answer surprised us too: You can use FSM's almost everywhere. In this talk we will do a recap on Finite State Machines, and show you some examples of where we use them at Telnyx. We will also show the transactions library and how we use this library to process FSMs in a distributed manner. And we end on a small demo of how you can use FSM machines in a real world application.