The introduction to Reactive Programming you've been missing

Abstraction: Practical tutorial on thinking in reactive streams using RxJS

Key points:

• Streams are sequences of ongoing events ordered in time; they emit values, errors, or a completed signal; subscribing to them is the Observer pattern
• Observable is "Promise++": a Promise is an Observable with one emitted value; Rx.Observable.fromPromise() converts between them
• flatMap flattens metastreams (stream of streams) into a single stream, essential for async HTTP responses
• combineLatest joins the two most recent values from two streams whenever either emits, enabling click-driven data refresh without re-requesting
• startWith() seeds a stream with an initial value, eliminating special startup logic
• Netflix uses RxJava as a key component for server-side concurrency in their API; Rx works equally well frontend and backend

Connections: Rxjs · Netflix · Reactive Programming · Functional Programming · Observables

Source: https://gist.github.com/staltz/868e7e9bc2a7b8c1f754