Beyond Basic Three-Tier: Why Strict Network Isolation Matters in Production AWS Architectures

Traditional three-tier AWS examples collapse critical security boundaries, allowing compromised frontend instances to access databases. This architecture enforces granular isolation through a four-tier network design where each layer communicates only with its intended downstream component. By demonstrating production-grade patterns with modular Terraform and dual load balancers, it reveals how real infrastructure requires deliberate architectural decisions that go far beyond tutorial simplicity.