cloud-costlisted

# Cloud Cost Optimization Cost optimization is not about spending less — it is about spending only on what creates value. ## Rightsizing The most expensive resource is the one you do not use. Identify idle resources (EC2 instances with < 5% CPU over 14 days, unattached EBS volumes, idle load balancers). Terminate them. This step alone typically saves 20-30% without any architectural change. ## Reserved and savings plans Commit to one-year or three-year terms for steady-state workloads. Convertible RIs for flexibility, Standard RIs for maximum discount. Savings Plans are simpler — they apply across instance families and regions. The break-even on a one-year RI is typically 6-7 months. If a workload will exist for a year, reserving it is not optional — it is basic financial hygiene. ## Spot instances For stateless, fault-tolerant, interruptible workloads. Batch processing, CI/CD runners, dev/test environments. Spot blocks for defined-duration workloads. The discount is 60-90% but the interruption rate varies by instance type and AZ — check the spot advisor before committing. ## Tagging and accountability Every resource must be tagged with `cost-center`, `environment`, `owner`. Untagged costs are unmanaged costs. Set up a budget alert at 80% of projected spend. A surprise bill is not a cloud problem — it is a tagging problem.