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Push-based Architectures with RxJS

9 min readMay 24, 2019

… all this time you have been coding wrong!

Before I can show you HOW to implement Push-Based architectures, I need to first describe WHY Pull-Based solutions are flawed… and WHY Push-Based systems are better.

Most developers learn to program, code, and build software architectures using traditional Pull-based approaches. In the world of web applications and asynchronous, rich user experiences this approach is flawed, rampant with myriad problems, and is fundamentally wrong.

Traditional Pull-Based Solutions

With Pull-based architecture, the views will explicitly call service methods to force-reload (aka ‘pull’) the data. This is the traditional approach employed by most developers.

Consider the simple function call findAllUsers() used to retrieve a list of users… here the code is pulling data to a view. If the user list subsequently changes, views (or services) must issue another pull request with findAllUsers(). But how do the views know when to issue another request?

Notice I have not stated whether the data is currently in-memory or must be retrieved from the server…

Excellent article Thomas Burleson. I have one question though.

Why do you classify event listeners as pull based? They just subscribe to an event (like you would subscribe to an observable) and “react” to events. They seem to behave like a push based system to me.

Hi Thomas, congratulations for the amazing article. Talking about errors, in a pull architecture we would use a try catch to show a “try again” button if the data is not received (in case of internet connection error or some api error). This is easy…