How I Found $12K/Year in AWS Waste Across 4 Accounts — Without Touching Production

How I Found $12K/Year in AWS Waste Across 4 Accounts — Without Touching Production Tags: aws finops cloudcost sre I joined a subsidiary of one of Korea's largest tech companies at the beginning of 2026 as the sole SRE. I inherited four AWS accounts — hub, shared, waitlist, and loyalty — connected via a Transit Gateway hub-spoke architecture. Each account ran its own mix of EKS clusters, RDS instances, Aurora clusters, legacy EC2 services, and networking stacks accumulated over several years by multiple teams. Nobody had done a cost audit since the accounts were created. Resources from decommissioned projects were still running. Log groups from deleted infrastructure were still ingesting. Six WorkSpaces that nobody had logged into for months were quietly billing $525/month. Within two weeks of part-time analysis and execution, I cut $644/month in immediate waste and identified a total of $933-1,017/month ($11.2-12.2K/year) across three workstreams — all without touching a single product