Multi-AZ carbon footprint calculator leveraging AWS WAF, ALB, CloudFront CDN, Lambda orchestration, and ML-powered scoring across isolated subnets in us-east-1a and us-east-1b. User requests flow through WAF and ALB to a React frontend, which calls a backend API that triggers Lambda orchestrators to coordinate data extraction, enrichment via ML, CO2e scoring, and personalized recommendations. The architecture spans four subnet tiers per AZ—public, application, processing, and data—with Emission DB and User DB replicated across zones for high availability and disaster recovery. This pattern demonstrates defense-in-depth (WAF + ALB), serverless compute scaling (Lambda), and data residency isolation, critical for compliance-heavy sustainability platforms. Fork this diagram on Diagrams.so to customize subnets, add cross-region failover, or integrate additional ML services. Consider adding VPC Flow Logs and CloudTrail for audit trails in production carbon accounting systems.