4.1 Project Overview

Overview of Project

Scenario

A growing e-commerce company receives hundreds of customer orders every day. Each order triggers multiple backend actions: recording the order, running business validations, processing it in the background, handling failures and retries, and notifying the team when something goes wrong. Right now, the company uses a single backend server that tries to perform all of this at once.

This creates several issues:

  • The system slows down during peak traffic
  • Failed orders are difficult to track
  • One failure can block the entire request
  • There is no retry mechanism
  • High-value orders do not receive special handling
  • No alerts are triggered when failures occur

To improve reliability and scale, the engineering team wants to move to a fully event-driven backend where each step runs independently, failures are isolated, and the system can scale on demand.

Your role as the Cloud Engineer

Your job is to redesign the entire order workflow using AWS managed services that support:

  • Instant order submission
  • Asynchronous processing
  • Dead-letter handling
  • Event-based routing
  • High-value order isolation
  • Alerts when failures occur

This project reflects how real e-commerce and SaaS platforms build reliable backend systems.

Our Solution

We will build a serverless, event-driven order pipeline using AWS services. Orders flow through API Gateway and Lambda into DynamoDB, trigger downstream processing via Streams, move through SQS for retries, route high-value items with EventBridge Pipes, and surface failures through a DLQ, CloudWatch alarms, and SNS alerts. The result is a scalable, reliable backend with no servers to manage.

About the Project

In this hands-on project, you will:

  • Build a frontend order submission app
  • Store orders and track their status in DynamoDB
  • Add SQS to handle retries and background processing
  • Build worker Lambdas that update order status and enforce business rules
  • Route high-value orders using EventBridge Pipes
  • Add a DLQ to capture unprocessed messages
  • Configure CloudWatch Alarms & SNS for real-time alerts

By the end, you will have a fully operational, distributed workflow — a strong Cloud Engineer portfolio project.

Steps To Be Performed 👩‍💻

We will walk through the following high-level steps:

  1. Build the Order Ingestion Layer (DynamoDB, Lambda, API Gateway, Frontend)
  2. Trigger downstream processing with DynamoDB Streams
  3. Add SQS for retries and resilient background processing
  4. Route high-value orders using EventBridge Pipes
  5. Add Dead-Letter Queue handling
  6. Configure alerts and observability

Services Used 🛠

  • Amazon API Gateway - Order submission endpoint
  • AWS Lambda - Business logic and workers
  • Amazon DynamoDB - Order storage
  • DynamoDB Streams - Real-time event triggers
  • Amazon SQS - Queueing and retries
  • Dead-Letter Queue (DLQ) - Failure isolation
  • Amazon EventBridge Pipes - Conditional routing
  • Amazon SNS - Failure notifications
  • Amazon CloudWatch - Metrics and alarms

Estimated Time & Cost ⚙️

  • Estimated Time: 3-4 hours
  • Cost: $0-$1

➡️ Architectural Diagram

Here is the architecture diagram:

➡️ Final Result

At the end of this project, you’ll have a fully working:

  • Event-driven order pipeline with real-time validation
  • Automatic retry handling
  • Separate high-value order routing
  • DLQ-based fault isolation
  • CloudWatch & SNS alerting

Complete and Continue