Building Event-driven Microservices with Node.js & Kafka

Tom Nagle
2 min readDec 21, 2022

Event-driven microservices are a design pattern for building scalable and resilient software systems. Instead of traditional monolithic architecture where all components are tightly coupled and execute in a predefined sequence, event-driven microservices decouple individual components and allow them to communicate and collaborate through the exchange of events.

This article is a condensed version of the video below.

In an event-driven microservices architecture, each microservice is designed to be small, modular, and independent, and it focuses on a specific business capability or functionality. These microservices communicate with each other through a messaging system, such as Apache Kafka, that acts as a central hub for exchanging events. This allows microservices to be loosely coupled and enables them to be developed, deployed, and scaled independently of one another.

One of the benefits of using event-driven microservices is that it enables the creation of highly scalable and resilient systems. Because each microservice is independent, it can be scaled up or down independently of other microservices, allowing the system to easily adapt to changing workloads. Additionally, because microservices are decoupled, a failure in one microservice will not bring down the entire system, ensuring high availability and fault tolerance.

To build event-driven microservices in node.js with Kafka, you can use the KafkaJS package, which provides a simple and easy-to-use API for working with Kafka in node.js. The first step is to install the KafkaJS package using npm or yarn:

npm i kafkajs
yarn add kafkajs

Next, you can create a new Kafka client and connect to the Kafka broker using the Kafka class from the KafkaJS package:

import { Kafka } from 'kafkajs'

const kafka = new Kafka({
clientId: 'my-app',
brokers: ['kafka1:9092', 'kafka2:9092']

const producer = kafka.producer()
const consumer =…
Tom Nagle

I am a full stack JavaScript developer, living in Melbourne, Australia. My preferred stack is Mongoose, TypeScript, Node.js, React & GraphQL.