When I think of running a Microservice on AWS, the first thing that comes to my mind is an Architecture that is scalable, highly available, and secure. The AWS Services that would help me with my requirements should definitely include a combination of Route 53, External Application Load Balancer (ALB) with path-based routing, EC2 Instances running in an Auto Scaling Group (ASG), Elastic Kubernetes Service (AKS), API Gateway + Lambda, and DynamoDB / Aurora.

"E-Commerce Web Application on AWS"

1. Situation (Background)

"Let us design a highly scalable eCommerce platform on AWS that allows users to browse products, add items to a cart, place orders, and process payments*. The goal is to ensure **high availability, fault tolerance, and cost optimization while handling traffic spikes, secure transactions, and real-time inventory updates**."*

2. Task (Challenges & Requirements)

"The key challenges and requirements generally include:"

Handling high traffic spikes (e.g., Sale Events, Black Friday Sales).
Scalability for frontend & backend services.
Secure payment processing with compliance standards (PCI DSS).
Fast product catalog search and real-time inventory management.
Multi-tier architecture with microservices-based separation of concerns.

3. Action (Design & AWS Services Used)

"To meet these requirements, Iet us build a microservices-based architecture using Route 53, ALB with path-based routing, EC2 ASG, EKS, API Gateway + Lambda, and Aurora/DynamoDB*."*

1. Domain Management & Traffic Routing

Used Amazon Route 53 for global DNS resolution.
Configured an External ALB to handle path-based routing:
- /products → Product Service
- /cart → Cart Service
- /checkout → Order & Payment Service

2. Backend Microservices (Three Possible Architectures Based on Use Case)

Depending on the use case, let us design three backend deployment models:

(A) EC2 Auto Scaling Group (ASG) + External ALB

Each microservice runs on EC2 instances in an Auto Scaling Group, behind an Application Load Balancer for load balancing.
ALB routes requests to specific target groups for different services.
Nginx + Node.js (or Spring Boot) hosted on EC2 to handle backend processing.
Auto Scaling Group (ASG) scales instances up/down based on CPU utilization.

(B) Amazon EKS (Kubernetes-based Microservices)

Containerized microservices deployed on Amazon EKS (Elastic Kubernetes Service).
ALB Ingress Controller for path-based routing to different pods.
Each microservice (Product, Cart, Order, Payment) runs as a separate Kubernetes deployment.
Horizontal Pod Autoscaler (HPA) adjusts pods based on traffic.

(C) API Gateway + Lambda (Serverless Approach)

We shall use the Amazon API Gateway to expose RESTful APIs.
Implemented AWS Lambda for business logic processing, including:
- Product catalog queries.
- Shopping cart updates.
- Order processing & payment handling (integrated with RazorPay/PayPal APIs).
- Stock validation before confirming purchases.

3. Data Storage & Processing

Product Catalog: Let us use Amazon DynamoDB with DAX (DynamoDB Accelerator) for fast product searches.
Order Management & Transactions: Amazon Aurora (PostgreSQL/MySQL) for transaction consistency.
Inventory Management: DynamoDB streams trigger Lambda functions to update stock levels in real-time.

4. Notifications & Asynchronous Processing

Amazon SNS + SQS for order confirmation & real-time notifications.
EventBridge + Step Functions to handle payment success & order fulfillment workflows.

5. Security & Compliance

AWS WAF + Shield for DDoS protection.
AWS IAM & Secrets Manager for managing credentials.
CloudTrail + GuardDuty for security monitoring.

6. Monitoring & Observability

Amazon CloudWatch + X-Ray for application performance monitoring.
AWS OpenSearch (Elasticsearch) for centralized logging & search analytics.

7. Result (Outcome & Impact)

"The microservice-based architecture should give us the following results"
✅ 99.99% uptime, handling high traffic during sales events.
✅ 50% cost reduction using DynamoDB auto-scaling and Lambda for serverless tasks.
✅ Fast product searches with DAX caching.
✅ Secure, compliant payments with PCI DSS encryption and AWS KMS.
✅ Seamless scaling with ALB & ASG or EKS HPA.

That is how I would approach a Microservices Architecture Design for an E-Commerce Web Application.

Like and Share the post with the community. Until next time.

Cheers, Feroze

How to design a Microservice for an E-commerce Web Application on AWS.