Explore functional reactive programming and its application in building large Single Page Applications (SPAs) in this JSConf US 2019 talk. Discover why RxJS and stream-based approaches were chosen for state management, side-effects handling, and complex data flow reasoning. Learn about the flexibility of RxJS in working with data streams and its role in decoupling monolithic applications. Examine the challenges and pitfalls encountered when utilizing RxJS Observables, and uncover emerging patterns. Dive into topics such as Redux with redux-observable, action streams for application-wide communication, routines, dead streams, advanced state streams including derived and proxy state, cold vs. hot observables, and view streams for data fetching. Evaluate the benefits of RxJS and streams, and consider whether embracing this approach is suitable for your projects.