How I Cut AWS Compute Costs by 70% with a Multi-Arch EKS Cluster and Karpenter

Faced with slow Kubernetes scaling and rising AWS bills, I replaced the Cluster Autoscaler with Karpenter, built a multi-architecture EKS cluster (AMD64 + ARM64) using Terraform, and shifted 70% of workloads to Spot Instances. The result: 70% lower compute costs, sub-20-second scaling, and significantly better resource utilization in production.