The three-tier architecture is the most widely adopted pattern for web applications on AWS. It separates concerns into a presentation tier (web servers or CDN), an application tier (business logic and API servers), and a data tier (databases and caches). This template gives you a pre-built, visually clear diagram that maps each tier to AWS services such as CloudFront, ALB, EC2 or ECS, and RDS, so you can document your production setup or plan a new deployment in minutes.
What Is a Three-Tier Architecture?
A three-tier architecture divides an application into three logical layers, each responsible for a distinct concern. The presentation tier handles user-facing requests through a CDN or web servers. The application tier runs business logic, APIs, and orchestration. The data tier stores persistent state in relational databases, caches, or object storage. This separation makes each layer independently scalable, deployable, and testable.
How This Template Maps to AWS Services
This diagram template maps each tier to specific AWS services so you can visualize a realistic production deployment.
- Presentation Tier: Amazon CloudFront, Application Load Balancer, Route 53 for DNS
- Application Tier: Amazon ECS or EC2 instances in an Auto Scaling Group across multiple Availability Zones
- Data Tier: Amazon RDS Multi-AZ for relational data, ElastiCache for session and query caching, S3 for static assets
Best Practices for Three-Tier Deployments
When using this architecture pattern, ensure each tier runs in private subnets where possible, with only the load balancer exposed to the internet. Use security groups and NACLs to restrict traffic between tiers. Enable auto-scaling on the application tier so you can handle traffic spikes without over-provisioning. Back up your RDS instances with automated snapshots and test failover regularly.
When to Use This Template
Use this template when you need to document an existing AWS web application for onboarding, architecture reviews, or compliance audits. It is also useful when planning a greenfield deployment and want to communicate the target architecture to your team or stakeholders before writing any infrastructure code.