This project demonstrates how to build a fully serverless event registration system using AWS services without relying on EC2 instances. It highlights the benefits of serverless design — scalability, cost efficiency, and reduced infrastructure overhead.

• Amazon S3 → Host the frontend (static HTML form).
• Amazon API Gateway → Connect frontend with backend securely.
• AWS Lambda → Handle validation and business logic.
• Amazon DynamoDB → Store registration details.
• Amazon SNS → Send confirmation notifications via email.
• Amazon CloudWatch → Debugging and log monitoring.
• AWS IAM → Manage secure permissions between services.

1. User opens the registration form hosted on S3.
2. On form submission → request sent to API Gateway (POST method).
3. API Gateway triggers Lambda function.
4. Lambda validates input (ensures no empty fields).
5. Valid data is stored in DynamoDB (Partition Key: eventID).
6. Lambda publishes a success notification to SNS.
7. User receives an email confirmation.

👤 User → 🪣 S3 (Frontend Hosting) → 🔗 API Gateway → λ Lambda
   → 📊 DynamoDB (DB Storage)
   → ✉️ SNS (Email Notification)
   → 📈 CloudWatch (Logs & Debugging)

• Create a role with Lambda as Use Case.
• Attach AmazonDynamoDBFullAccess policy.
• Attach AmazonSNSFullAccess policy.

• Validates that no field is empty.
• Writes data into DynamoDB.
• Publishes confirmation email using SNS.

1. DynamoDB → Create table EventRegistration with eventID as Partition Key.

2. IAM → Create role for Lambda with DynamoDB + SNS permissions.

3. Lambda → Write and deploy function with created role.

4. SNS → Create topic FormSubmissionTopic and subscribe an email.

5. API Gateway → Create REST API → resource /register → method POST.

   • Enable Lambda Proxy Integration.
   • Deploy API and get endpoint URL.

6. S3 → Upload frontend HTML/JS → enable static website hosting.

   • Update form action URL with API Gateway endpoint.

7. CloudWatch → Monitor logs and debug issues.

• Issue: Form submission worked in Lambda test console but failed via S3 frontend with error:

  "statusCode": 405, "body": "{\"error\": \"Method not allowed\"}"
  

• Root Cause: API Gateway method wasn’t configured with Lambda Proxy Integration.

• Fix: Enabled Proxy Integration → request passed correctly → system worked end-to-end ✅.

Architectural Diagram

Project Flow

Event Registration Form

DynamoDB Table

CloudWatch Logs

SNS Service

• Serverless saves resources compared to EC2 hosting.
• Debugging with CloudWatch is essential when API calls silently fail.
• Proper API Gateway + Lambda integration is key for smooth workflows.