Lesson 4.1:
Microservices 101

Decoupling the Core

Microservices allow teams to build and deploy independent parts of a system. The key to successful microservices is **Loose Coupling** and **High Cohesion**.

The API Gateway Pattern

A single entry point for all clients, the API gateway handles routing, load balancing, and authentication, hiding the complexity of the underlying services.

// Example: Express as a simple API Gateway proxy
import express from 'express';
import { createProxyMiddleware } from 'http-proxy-middleware';

const app = express();
app.use('/users', createProxyMiddleware({ target: 'http://user-service:8080' }));

Event-Driven Communication

Synchronous requests create bottlenecks. Modern systems use message queues (RabbitMQ, Kafka, Redis) to communicate asynchronously.

Check Your Knowledge

What is the main advantage of event-driven communication?

• Reduced Coupling
• Instant Performance