State machines are incredibly useful and I use them all the time when I write UI code. There are a couple benefits that come to mind with respect to writing UI

State machines are incredibly useful and I use them all the time when I write UI code. There are a couple benefits that come to mind with respect to writing UI. First, it forces you think through all the potential "inputs" on your system, be they button presses from users or network request responses. You have to be explicit about what could have an effect on the system. Secondly, it makes your business logic easier to reason about because you essentially turn your UI code into a bunch of functional statements. All your transitions are just pure functions where the input is the previous state and some input, and the output is the new state. A lot of UI frameworks do it this way today, of course, but I picked up from reading about how Elm works. Whenever I write new UI from scratch, I always end up falling back on the state machine for guidance.