I Built an AI-Powered AWS Cost Optimizer — Here's How It Works

I'm an AWS consultant. My clients always ask the same question: "Why is my AWS bill so high?" The answer is always the same: idle resources, oversized instances, and services nobody remembered to turn off. So I built a tool to find them automatically. The Architecture Sharktooth connects to a customer's AWS account via a cross-account IAM role — the same pattern used by Datadog, CloudHealth, and AWS's own tools. Customer AWS Account Sharktooth AWS Account ┌─────────────────┐ ┌──────────────────────┐ │ │ │ │ │ IAM Role ◄──────────────── STS AssumeRole │ │ (read-only) │ │ + ExternalId │ │ │ │ │ │ Cost Explorer │ │ Cost Analysis │ │ CloudWatch │────────► │ AI Recommendations │ │ EC2 Describe │ │ Dashboard │ │ RDS Describe │ │ │ └─────────────────┘ └──────────────────────┘ Step 1: Connect (5 minutes) The customer creates a read-only IAM role with this trust policy: { "Version" : "2012-10-17" , "Statement" : [{ "Effect" : "Allow" , "Principal" : { "AWS" : "arn:aws:iam::SHARKTOOTH_ACCOUNT:ro