E-Commerce Platform — Microservices Architecture

Stack: Node.js · Express · MongoDB Atlas · RabbitMQ · AWS S3 · AWS SES · Stripe · Razorpay · Docker · GitHub Actions · AWS EC2

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Architecture Overview

                         ┌─────────────────┐
  Browser / Mobile  ───► │   API Gateway   │ :3000
                         │  (auth, proxy,  │
                         │  rate limiting) │
                         └────────┬────────┘
                                  │
          ┌───────────────────────┼───────────────────────┐
          ▼                       ▼                       ▼
   ┌─────────────┐       ┌─────────────────┐     ┌──────────────┐
   │ user-svc    │       │  product-svc    │     │  cart-svc    │
   │ :4001       │       │  :4002          │     │  :4003       │
   └─────────────┘       └─────────────────┘     └──────────────┘

   ┌─────────────┐       ┌─────────────────┐
   │ order-svc   │       │  payment-svc    │
   │ :4004       │       │  :4005          │
   └──────┬──────┘       └───────┬─────────┘
          │                      │
          └──────────┬───────────┘
                     ▼
          ┌──────────────────────┐
          │   RabbitMQ Exchange  │  ecommerce.events (topic)
          └──────────┬───────────┘
                     │
        ┌────────────┼────────────┐
        ▼                         ▼
┌──────────────┐       ┌────────────────────────┐
│ email-svc    │       │  notification-svc       │
│ (AWS SES)    │       │  (app notifications)    │
└──────────────┘       └────────────────────────┘

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Services

Service	Port	Database	Responsibilities
API Gateway	3000	—	Auth, routing, rate limiting, CORS
user-service	4001	ecommerce-users	Register, login, admin auth
product-service	4002	ecommerce-products	Product CRUD, S3 image upload
cart-service	4003	ecommerce-users	Cart read/write
order-service	4004	ecommerce-orders	Order lifecycle, status updates
payment-service	4005	ecommerce-orders	Stripe, Razorpay, payment verification
email-service	—	—	AWS SES consumer, sends all emails
notification-service	4007	—	App notification consumer

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RabbitMQ Event Flow

user-service     → user.registered      → email-service (welcome email)
order-service    → order.placed         → email-service (order confirmation)
payment-service  → payment.done         → email-service (payment receipt)
order-service    → order.status_updated → email-service + notification-service

Exchange: ecommerce.events (topic, durable) Queues: email.notifications, app.notifications

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Quick Start (Local Development)

Prerequisites

• Docker Desktop
• AWS account (for S3 + SES) — see .env.example

1. Clone and configure

git clone https://github.com/YOUR_USERNAME/ecommerce-app.git
cd ecommerce-app

# Create root .env from example
cp .env.example .env
# Fill in all values in .env

2. Start all services

docker compose up --build

This starts:

• RabbitMQ management UI → http://localhost:15672 (guest/guest)
• API Gateway → http://localhost:3000
• Frontend → http://localhost:5173
• Admin panel → http://localhost:5174

3. Verify services are healthy

# Check all service health endpoints
curl http://localhost:3000/health         # Gateway
curl http://localhost:4001/health         # User service
curl http://localhost:4002/health         # Product service
curl http://localhost:4003/health         # Cart service
curl http://localhost:4004/health         # Order service
curl http://localhost:4005/health         # Payment service

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API Reference

All requests go through the gateway at :3000.

Method	Path	Auth	Description
POST	/api/user/register	None	Register new user
POST	/api/user/login	None	Login user
POST	/api/user/admin	None	Admin login
GET	/api/product/list	None	List all products
POST	/api/product/single	None	Get single product
POST	/api/product/add	Admin	Add product + S3 upload
POST	/api/product/remove	Admin	Delete product
POST	/api/cart/get	User JWT	Get cart
POST	/api/cart/add	User JWT	Add to cart
POST	/api/cart/update	User JWT	Update cart item
POST	/api/order/place	User JWT	Place COD order
POST	/api/order/stripe	User JWT	Create Stripe session
POST	/api/order/verifyStripe	User JWT	Verify Stripe payment
POST	/api/order/razorpay	User JWT	Create Razorpay order
POST	/api/order/verifyRazorpay	User JWT	Verify Razorpay payment
POST	/api/order/userorders	User JWT	Get user's orders
POST	/api/order/list	Admin	Get all orders
POST	/api/order/status	Admin	Update order status

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Project Structure

ecommerce-app/
│
├── frontend/              React + Vite (unchanged)
├── admin/                 React + Vite (unchanged)
├── backend/               Legacy monolith (backup, disabled in compose)
│
├── gateway/               API Gateway (port 3000)
│   ├── src/middleware/    auth, rateLimiter, requestLogger
│   ├── src/routes/        proxy route config
│   └── server.js
│
├── services/
│   ├── user-service/      Port 4001 — ecommerce-users DB
│   ├── product-service/   Port 4002 — ecommerce-products DB
│   ├── cart-service/      Port 4003 — ecommerce-users DB
│   ├── order-service/     Port 4004 — ecommerce-orders DB
│   ├── payment-service/   Port 4005 — ecommerce-orders DB
│   ├── email-service/     SES consumer, no HTTP port
│   └── notification-svc/  Port 4007 — RabbitMQ consumer
│
├── shared/                Shared libraries (imported by all services)
│   ├── config/            mongodb.js, rabbitmq.js
│   ├── middlewares/       auth.js, adminAuth.js
│   ├── utils/             logger.js, responseHelper.js, errorHandler.js, s3Upload.js
│   └── events/            eventKeys.js (routing key constants)
│
├── docker/
│   └── nginx/             nginx.conf, Dockerfile
│
├── .github/workflows/     deploy.yml — CI/CD pipeline
├── docker-compose.yml     Development (all services)
├── docker-compose.prod.yml Production (with Nginx, no local MongoDB)
└── .env.example           Master environment variable reference

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CI/CD Pipeline

On every push to main:

Push to main
    │
    ▼
Build Docker images (all services, cached)
    │
    ▼
Push to Docker Hub (tagged with SHA + latest)
    │
    ▼
SSH into EC2
    │
    ├── git pull origin main
    ├── docker compose pull
    ├── docker compose up -d --remove-orphans
    ├── Health check (curl /health)
    └── docker image prune -f

GitHub Secrets required:

• DOCKER_USERNAME, DOCKER_PASSWORD
• EC2_HOST, EC2_USER, EC2_SSH_KEY, EC2_APP_DIR

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EC2 Production Deployment

# On EC2 (first time setup)
sudo apt update && sudo apt install -y docker.io docker-compose-plugin git
git clone https://github.com/YOUR_USERNAME/ecommerce-app.git
cd ecommerce-app
cp .env.example .env
# Edit .env with production values
nano .env

# Start in production mode
docker compose -f docker-compose.prod.yml up -d

# View logs
docker compose -f docker-compose.prod.yml logs -f gateway

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Environment Variables

See .env.example for the complete reference.

Each service also has its own .env.example with only the variables it needs.

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Legacy Backend

The original monolithic backend/ is preserved as a rollback option.

# Start legacy backend alongside new services
docker compose --profile legacy up -d backend

# Or run standalone
cd backend && node server.js

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Technology Stack

Layer	Technology
Runtime	Node.js 20
Framework	Express.js v5
Database	MongoDB Atlas (Mongoose)
Message Broker	RabbitMQ 3
Email	AWS SES (SDK v3)
Storage	AWS S3 (SDK v3)
Payments	Stripe + Razorpay
Auth	JWT (jsonwebtoken)
Container	Docker + Docker Compose
Proxy	Nginx
CI/CD	GitHub Actions
Cloud	AWS EC2