Imported from jeremylongshore/tons-of-skills-marketplace (
skills/.curated/optimizing-cloud-costs/SKILL.md). Install upstream withnpx skills add jeremylongshore/tons-of-skills-marketplace --skill optimizing-cloud-costs. Copyright stays with the author (MIT).
Optimizing Cloud Costs
Overview
Analyze cloud spending across AWS, GCP, and Azure to identify waste, recommend rightsizing, and generate cost-saving configurations. Covers reserved instances, spot/preemptible workloads, storage tiering, idle resource cleanup, and budget alerting using cloud-native cost management APIs.
Prerequisites
- Cloud provider CLI authenticated with billing/cost-explorer read access
- AWS:
ce:GetCostAndUsage,ec2:DescribeInstances,cloudwatch:GetMetricDatapermissions - GCP: Billing Account Viewer and Compute Viewer roles
- Azure: Cost Management Reader role
- Access to current infrastructure-as-code (Terraform, CloudFormation) for rightsizing changes
- At least 30 days of billing data for meaningful analysis
Instructions
- Pull current cost data using cloud cost APIs (
aws ce get-cost-and-usage,gcloud billing budgets list) - Identify the top 10 cost drivers by service, region, and resource tag
- Detect idle resources: instances with < 5% average CPU over 14 days, unattached EBS volumes, unused Elastic IPs, orphaned snapshots
- Recommend rightsizing: compare instance utilization against available instance types and suggest downsizing
- Evaluate reserved instance or savings plan coverage against on-demand spend; recommend commitments for steady-state workloads
- Identify spot/preemptible candidates: stateless, fault-tolerant workloads (batch jobs, CI runners, dev environments)
- Review storage costs: recommend S3 Intelligent-Tiering, lifecycle policies for infrequent access, or Glacier for archives
- Generate Terraform/IaC changes to implement approved optimizations
- Set up budget alerts with thresholds at 50%, 80%, and 100% of monthly budget
- Create a cost optimization report summarizing findings, savings estimates, and implementation priority
Output
- Cost analysis report with per-service breakdown and savings recommendations
- Terraform/CloudFormation changes for rightsizing and reserved instance purchases
- S3 lifecycle policy configurations for storage tiering
- Budget alert configurations (CloudWatch, GCP Budget, Azure Cost Alerts)
- Cleanup scripts for idle resources (with dry-run mode for safety)
Error Handling
| Error | Cause | Solution |
|---|---|---|
Access Denied on Cost Explorer API |
Missing ce:* IAM permissions |
Attach the AWSBillingReadOnlyAccess managed policy to the IAM user/role |
No billing data available |
Account is too new or cost export not enabled | Enable Cost Explorer (takes 24h to populate) or set up CUR (Cost and Usage Report) |
Rightsizing recommendation breaks workload |
Instance too small for peak load | Base sizing on P95 utilization, not average; keep a 20% headroom buffer |
Spot instance terminated mid-job |
Spot capacity reclaimed by provider | Use spot fleet with diversified instance types and implement checkpointing |
Budget alert not firing |
SNS topic or notification channel misconfigured | Verify SNS subscription is confirmed and test with a low threshold |
Examples
- "Analyze AWS costs for the last 3 months, identify the top waste areas, and generate a cleanup script for unattached EBS volumes and unused Elastic IPs."
- "Compare on-demand EC2 spend against Savings Plans pricing and recommend 1-year commitments for steady-state workloads."
- "Create S3 lifecycle policies to move objects older than 90 days to Glacier and delete after 365 days across all buckets tagged
env:production."
Resources
- AWS Cost Explorer: https://docs.aws.amazon.com/cost-management/latest/userguide/ce-what-is.html
- GCP Cost Management: https://cloud.google.com/billing/docs/how-to/budgets
- Azure Cost Management: https://learn.microsoft.com/en-us/azure/cost-management-billing/
- FinOps Foundation: https://www.finops.org/framework/