Nodejs/Express Microservices - User, Product & Order Microservice Architecture

This repository contains the Product and Order microservices for an E-Commerce application, implemented using Node.js, TypeScript, MongoDB, and RabbitMQ. The system follows an event-driven architecture to manage product availability, orders

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Microservices Overview

1. Product Microservice

Responsible for:

• Managing product data (CRUD)
• Verifying product availability
• Decrementing product stock on order creation

Database Operations:

• create / createMany → Add new products to the DB.
• verifyAvailability → Checks stock for given items.
• decrementStock → Reduce stock quantities after order is placed.

RabbitMQ Events:

• Consumes:
  • order.verify → Verify product availability for an order.
  • order.stock.decrement → Decrement stock when an order is created.
• Publishes:
  • order.verify.result → Sends verification results back to Order Microservice.

Flow Example:

1. Order Microservice publishes order.verify.
2. Product Microservice verifies stock and replies with order.verify.result.
3. Order Microservice creates order if verification is successful.
4. Order Microservice publishes order.stock.decrement.
5. Product Microservice decrements stock accordingly.

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2. Order Microservice

Responsible for:

• Handling orders
• Managing order verification workflow

RabbitMQ Events:

• Consumes:
  • order.verify.result → Receive product verification result from Product Microservice.
• Publishes:
  • order.verify → Request product verification before order creation.
  • order.stock.decrement → Request stock decrement after order creation.

Flow Example:

3. When placing an order:
   • Publish order.verify.
   • Wait for order.verify.result.
   • If verification succeeds, create order in DB.
   • Publish order.stock.decrement to update product stock.

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Event Flow Summary

Event	Publisher	Consumer	Purpose
order.verify	Order Microservice	Product Microservice	Check product availability
order.verify.result	Product Microservice	Order Microservice	Return verification result
order.stock.decrement	Order Microservice	Product Microservice	Decrement product stock after order