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Suiunbek Isaev
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Case study

AWS Infrastructure Cost Optimization

Automation that finds idle EC2 capacity and routes it to the owning team for action, delivering approximately $500K in annual savings.

Result
~$500K in annual AWS savings
Role
Built
Where
Capital One · 2025 – Present
Key stack
Python · Boto3 · AWS EC2 · CloudWatch metrics

Sanitized case study based on professional experience. Internal names, accounts, hostnames and configurations are intentionally omitted.

01Problem

Idle and underutilized EC2 instances accumulated across AWS accounts. Nobody had a reliable, repeatable way to find them and get the owning team to act.

02Context

In a large multi-account estate, the hard part is usually ownership rather than detection: knowing who can safely decide whether a resource is still needed. The same review process also covered EMR, load balancers, target groups and Route 53 resources.

03Architecture

Sanitized conceptual architecture based on professional experience.

How it works

  • Automation scans EC2 utilization across accounts and flags idle or underutilized instances.
  • Ownership is resolved from resource tags, and the owning application team gets a targeted email alert.
  • The team confirms usage and dependencies, then deletes or downsizes the instance.
  • Savings are measured and the scan repeats, which turns a one-off cleanup into ongoing governance.

04Engineering approach

  1. Identify underutilized resources from utilization data.
  2. Identify ownership through resource tags.
  3. Validate usage with the owning team.
  4. Confirm application dependencies before any change.
  5. Decommission or right-size where appropriate.
  6. Measure savings.
  7. Establish repeatable governance by running the process on a schedule.

05Security

  • The automation reports and notifies, and destructive actions stay with the owning team after validation.
  • Tag-based ownership reinforces tagging standards across accounts.

06Automation

  • Scheduled detection of idle EC2 instances.
  • Tag-based routing of alerts to the right team.
  • Repeatable loop instead of periodic manual audits.

07Results

~$500Kannual AWS savings

≈ $42Kper month (derived: annual ÷ 12)

Month 1Month 12 → ~$500K
  • Approximately $500K in annual AWS savings.
  • Owners get actionable, targeted notifications instead of broad cleanup requests.

08Lessons learned

  • Detection is easy and ownership is hard, so good tagging is what makes cost automation work.
  • Keeping the final decision with the owning team builds trust and avoids outages.

09Skills & technologies

FinOpsPython / Boto3AWS governanceStakeholder coordination
PythonBoto3AWS EC2CloudWatch metricsResource taggingEmail notifications