RxJS

Reactive Extensions Library for JavaScript — compose async and event-based programs.

RxJS (Reactive Extensions for JavaScript) is a library for composing asynchronous and event-based programs using observable sequences. It provides a powerful set of operators to filter, transform, combine, and manage streams of data over time. With concepts like Subjects, BehaviorSubjects, and schedulers for controlling concurrency, RxJS handles everything from simple DOM events to complex real-time data flows. Its declarative approach simplifies callback and promise orchestration, making it easier to reason about asynchronous logic, error handling, and resource cleanup in large-scale applications.