Lately, in the front-end world, we have focused our efforts on isolating the state and having cleaner ways to deal with it. Redux is a good example of what our efforts has produced.

But state management is not the end of our journey to a cleaner code. We still need to deal with what actually mutate the state: Time.

State can easily be derived from time. What if we defined our applications as functions of time instead of functions of state?

We’ll see together how Reactive Programming and Cycle.js can help us building applications as pure functions of time.