Learn how to implement event-driven communication in Java microservices using Kafka. Step-by-step guide with real-world e-commerce example and full working code.

Ramesh Fadatare

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5 min read

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Apr 30, 2025

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🔒 This is a Medium member-only article. If you’re not a Medium member, you can read the full article for free on my blog: How to Implement Event-Driven Communication in Java Microservices.

🧾 Introduction

Event-Driven Communication is the backbone of modern, scalable microservices architectures.

✅ Instead of tight synchronous REST calls, services communicate via events asynchronously.
✅ It improves scalability, resilience, and flexibility.

In this guide, you’ll learn how to implement Event-Driven Microservices using Kafka — through a real-world e-commerce example:

✅ Project Setup: E-Commerce Microservices System

We’ll build a system with 3 services:

Communication Style: Services publish and listen to Kafka events.

📦 Step 1: Set Up Kafka Locally

You need a running Kafka instance. Use Docker Compose for simplicity.

# docker-compose.yml
version: '3'
services:
  zookeeper:
    image: wurstmeister/zookeeper
    ports:
      - "2181:2181"
  kafka:
    image: wurstmeister/kafka
    ports:
      - "9092:9092"
    environment:
      KAFKA_ADVERTISED_HOST_NAME: localhost
      KAFKA_ZOOKEEPER_CONNECT: zookeeper:2181

➡️ Run:

docker-compose up

✅ Kafka broker running at localhost:9092.

📦 Step 2: Create Order Service (Producer)