Introduction to Reactiveness

The real world is pretty messy: Events happen in a random order, applications crash, and networks fail. Only a few applications are completely synchronous, and writing asynchronous code is necessary to keep applications responsive. Most of the time it’s downright painful, but it really doesn’t have to be.

Modern applications need super-fast responses and the ability to process data from different sources at the same time without missing a beat. Current techniques won’t get us there because they don’t scale—code becomes exponentially more complex as we add concurrency and application state.