Design a globally scalable infrastructure for a cloud-native e-commerce platform using Terraform, ensuring high availability, disaster recovery, and cost optimization. Discuss trade-offs between multi-region vs single-region architectures, state management strategies, and auto-scaling patterns.

Design a globally scalable infrastructure using Terraform by deploying a multi-region architecture with load balancers, auto-scaling groups, and distributed databases. Use Terraform modules for consistency and version control. Implement disaster recovery via cross-region replication and state management with Terraform remote state and Consul. Optimize costs using spot instances, reserved instances, and auto-scaling policies. Discuss trade-offs: multi-region offers resilience but increases complexity and cost, while single-region reduces latency but risks downtime. Prioritize stateless services and use managed databases for high availability. Auto-scaling patterns include Kubernetes HPA and AWS ASG for dynamic workloads.

The infrastructure leverages Terraform to provision a multi-region architecture with primary and secondary regions, ensuring high availability via global load balancers (e.g., AWS Global Accelerator) and cross-region DNS failover. Auto-scaling is achieved using Kubernetes Horizontal Pod Autoscaler (HPA) for microservices and AWS Auto Scaling Groups (ASG) for compute-heavy tasks. State management employs Terraform remote state with backend storage (e.g., S3 + DynamoDB) and Consul for distributed service discovery and configuration. Disaster recovery is implemented through cross-region database replication (e.g., Aurora Global Database) and regular backups to S3 with versioning. Cost optimization includes spot instances for non-critical workloads, reserved instances for steady-state resources, and auto-scaling cooldown periods to prevent over-provisioning. Multi-region architectures provide resilience against regional outages but increase latency and operational complexity compared to single-region setups, which are cheaper but risk downtime. State management prioritizes consistency with Terraform workspaces and Consul’s leader election for fault tolerance. Auto-scaling patterns balance performance and cost by leveraging metrics from CloudWatch and Prometheus.