Build a 3-Tier Web Architecture on AWS Using Amplify, Lambda & RDS (MySQL)

Creating a 3-tier architecture on AWS is a great way to build scalable, secure, and decoupled applications. In this guide, I’ll walk you through the high-level steps to integrate your frontend (Amplify), backend (Lambda), and database (RDS MySQL).

3-Tier Architecture Overview

• Presentation Layer – Built with React, hosted on AWS Amplify

• Logic Layer – Serverless backend using AWS Lambda + API Gateway

• Data Layer – MySQL database on Amazon RDS

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1. Frontend (AWS Amplify)

• Deploy your React app to Amplify.

• Add environment variables for backend API URL.

(Full blog on frontend: [AWS Amplify])

2. Backend (Lambda + API Gateway)

• Build your Express.js app.

• Connect to RDS using mysql2 or sequelize.

• Deploy it to Lambda via ZIP or using Serverless Framework.

• Expose APIs through API Gateway.

(Full blog on backend: [AWS Lambda])

3. Database (RDS MySQL)

• Launch RDS MySQL in a private subnet (for security).

• Make sure to enable public access only if needed for dev.

• Note the DB endpoint, username, and password.

(Full blog on RDS: [AWS RDS])

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Connecting the Layers

• Lambda ↔ RDS:
  Ensure Lambda is in the same VPC as RDS (or connected via VPC connector).
  Configure security groups to allow Lambda access to the DB port (3306).

• Amplify ↔ Lambda:
  Use the API Gateway endpoint in your frontend code to call backend APIs.

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Common Pitfalls

1. Lambda can’t connect to RDS?

   • Check VPC, subnet, and security group settings.

   • Ensure Lambda has timeout > 10 seconds (cold starts + DB connection time).

2. CORS issues from Amplify?

   • Make sure your Lambda/API Gateway is sending proper CORS headers.

3. DB connection timeouts?

   • Use connection pooling in backend.

   • Avoid opening new connections on each request.

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✅Summary

With these 3 layers connected properly, you get a robust architecture:

• Secure, isolated DB layer

• Scalable, event-driven backend

• Fast, globally hosted frontend

For in-depth tutorials, check the detailed blogs on each component mentioned above.

Feel free to contact me if you need help setting this up!