RxJS in Angular: Best Practices for Handling Asynchronous Data

Ibrahim Jaber
4 min readApr 11

Asynchronous data management is a crucial aspect of building modern web applications, and Angular provides a powerful toolset for handling asynchronous operations. At the heart of this toolset is RxJS, a library for reactive programming that allows developers to work with asynchronous data streams using a simple and consistent API. However, mastering RxJS can be a daunting task, especially for developers new to Angular or reactive programming.

In this blog, we will guide you through the best practices for using RxJS in an Angular application. We will use a fun business problem as an example to demonstrate how to effectively manage asynchronous data using RxJS operators and techniques. Whether you’re a beginner or an experienced Angular developer, this guide will help you write clean, efficient, and maintainable code when working with asynchronous data in your applications. So, let’s dive in and explore the world of RxJS in Angular!

Here are some best practices to follow when using RxJS in an Angular application:

Use observables to manage asynchronous data

When working with asynchronous data, it’s best to use observables to manage the flow of data. Observables allow you to work with streams of data over time, and they provide many useful operators that make it easier to handle data.

In our example, we can create an observable to fetch the list of friends from the API using the HttpClient module in Angular:

import { HttpClient } from '@angular/common/http';
import { Observable } from 'rxjs';


getFriends(): Observable<Friend[]> {
return this.http.get<Friend[]>('/api/friends');

Use operators to transform data

RxJS provides many operators that can be used to transform and manipulate data in the stream. This can include filtering, mapping, reducing, and more.

For example, let’s say we want to display the number of friends that a user has. We can use the map operator to transform the response from the API to just return the length of the array:

import { map } from 'rxjs/operators';


getFriendCount(): Observable<number> {
return this.getFriends().pipe(
map(friends => friends.length)

Use subjects for sharing data between components



Ibrahim Jaber

Software developer | Programming and Blockchain enthusiast