King coder

Posted on Oct 15

Ultimate Microservices Learning Guide (Node.js + Express.js)

#microservices #node #tutorial #beginners

This is a complete roadmap for learning Microservices Architecture from scratch, specifically using Node.js and Express.js. It's designed for beginners or students with little to no experience in large-scale systems.

📘 What You'll Learn

1. 🧱 Microservices Basics

Monolithic vs Microservices architecture
Benefits and challenges
When to use Microservices
Real-world examples: Netflix, Uber, Amazon
Principles: Loosely Coupled, Independently Deployable
Domain-Driven Design (DDD), Bounded Context

2. ⚙️ Setting Up Node.js Microservices

Build REST APIs using Express.js
Folder structure for microservices
Creating multiple services (user, auth, product, order, etc.)
Using environment variables (.env) with dotenv
Use Docker to containerize services
Connecting services with MongoDB, PostgreSQL, etc.

3. 🔗 Service Communication

Synchronous: REST APIs with Axios or Fetch
Asynchronous: Kafka, RabbitMQ
Choosing sync vs async communication

4. 🌐 API Gateway

What is an API Gateway and why use it
Tools: Kong, NGINX, Spring Cloud Gateway (Java alt)
Features: Routing, Authentication, Rate Limiting, Aggregation

5. 🔐 Authentication & Authorization

JWT-based Auth with Node.js
Role-Based Access Control (RBAC)
OAuth2 Overview
Centralized Authentication Service

6. 🧭 Service Discovery

Why we need it
Using Consul for Node.js
Health checks and dynamic service registration

7. ⚙️ Configuration Management

Using .env and dotenv
Centralized config with Consul or Vault
Managing secrets securely

8. 📈 Logging, Monitoring & Tracing

Logging: winston, morgan
Centralized Logging: ELK Stack
Metrics with Prometheus & Grafana
Distributed Tracing with Jaeger or OpenTelemetry

9. 🧪 Testing Microservices

Unit Testing: Jest, Mocha
Integration Testing: Supertest
Contract Testing: Pact
End-to-End Testing: Cypress

10. 🐳 Docker & Kubernetes

Containerize services with Docker
Use Docker Compose for local dev
Deploy services with Kubernetes (K8s)
Concepts: pods, deployments, services, ingress

11. 🚀 CI/CD Pipeline

Automate builds and tests using GitHub Actions or Jenkins
Docker image build and push
Auto-deployment to K8s
Blue/Green & Canary deployments

12. 📬 Event-Driven Architecture

Kafka or RabbitMQ integration
Event producers and consumers
Event Sourcing concepts
Message queues for scalability

13. 💾 Data Consistency

Eventual consistency between services
Saga Pattern (Orchestration & Choreography)
Avoiding distributed transactions (2PC)

14. 🧠 Resilience and Fault Tolerance

Retry, Timeout, Circuit Breaker
Libraries: opossum for Node.js
Rate limiting and fallback strategies

15. 🔍 Real-World Microservices Project

Example Project: E-Commerce System

Includes services:

Auth Service
User Service
Product Service
Cart Service
Order Service
Payment Service
Notification Service

📚 Recommended Tools & Libraries

Purpose	Tool/Library
API Framework	Express.js
Auth & JWT	jsonwebtoken, passport
Database	Mongoose, Sequelize
Messaging	KafkaJS, amqplib
Config	dotenv
Logging	winston, morgan
Tracing	OpenTelemetry
Testing	Jest, Mocha, Supertest
Resilience	opossum
Containerization	Docker, Docker Compose
Orchestration	Kubernetes
Monitoring	Prometheus, Grafana

🗓️ Suggested Weekly Learning Plan

Week	Topics
1	Basics of Microservices, REST API with Express
2	Docker & Multi-Service Setup
3	API Gateway, Auth with JWT
4	Async Communication (Kafka/RabbitMQ)
5	Service Discovery, Central Config
6	Logging, Monitoring, Tracing
7	CI/CD Pipelines
8	Kubernetes Deployment
9	Event-Driven Architecture
10	Build and Deploy Real-World App

📺 Free Learning Resources

💡 Final Tips

Start small (2-3 services), then scale
Use Docker Compose for local development
Don’t over-engineer early — simplicity wins
Focus on clean code and consistent APIs
Document everything (Swagger/OpenAPI)

📌 Want this as a Notion, PDF, or GitHub Template?

Feel free to copy this into your personal tools, or ask for a downloadable version!

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