Ops Cost Optimization

Cost Optimization Workflow

This skill defines the structured process for cloud cost optimization. Use it for systematic cost analysis and data-driven optimization.

Cost Optimization Phases

Phase 1: Cost Visibility

Cost Breakdown Dimensions

Analyze costs across multiple dimensions:

Cost Visibility Template

## Cost Visibility Report

**Period:** [Month YYYY]
**Total Spend:** $XX,XXX
**Budget:** $XX,XXX
**Variance:** [+/-X%]

### Cost by Service

| Service | Cost | % of Total | MoM Change |
|---------|------|------------|------------|
| EC2 | $X,XXX | XX% | +X% |
| RDS | $X,XXX | XX% | +X% |
| S3 | $X,XXX | XX% | +X% |
| Data Transfer | $X,XXX | XX% | +X% |
| Other | $X,XXX | XX% | +X% |

### Cost by Environment

| Environment | Cost | % of Total |
|-------------|------|------------|
| Production | $X,XXX | XX% |
| Staging | $X,XXX | XX% |
| Development | $X,XXX | XX% |

### Cost by Team

| Team | Cost | % of Total |
|------|------|------------|
| Platform | $X,XXX | XX% |
| API | $X,XXX | XX% |
| Data | $X,XXX | XX% |

Tagging Requirements

Minimum required tags for cost allocation:

Phase 2: Anomaly Detection

Anomaly Detection Rules

Anomaly Investigation

When anomaly detected:

1. Identify the spike:

   • Which service/resource?
   • When did it start?
   • What changed?

2. Check common causes:

   • New deployment
   • Traffic increase
   • Data growth
   • Misconfiguration
   • Forgotten resources

3. Validate intentionality:

   • Expected growth?
   • Approved change?
   • One-time vs recurring?

Anomaly Report Template

## Cost Anomaly Report

**Detected:** YYYY-MM-DD HH:MM
**Severity:** [Critical/Warning/Info]

### Anomaly Details

| Metric | Expected | Actual | Delta |
|--------|----------|--------|-------|
| Daily spend | $X,XXX | $X,XXX | +XX% |

### Investigation

**Root Cause:** [description]

**Contributing Factors:**
1. [Factor 1]
2. [Factor 2]

**Intentional:** [Yes/No]

### Action Required

- [ ] [Action if remediation needed]
- [ ] [Update budget if expected]

Phase 3: Optimization Analysis

Optimization Categories

Rightsizing Analysis

## Rightsizing Opportunities

### Underutilized Instances

| Instance | Type | Avg CPU | Avg Mem | Recommendation | Savings |
|----------|------|---------|---------|----------------|---------|
| api-prod-1 | m5.xlarge | 15% | 25% | m5.large | $70/mo |
| worker-2 | c5.2xlarge | 30% | 20% | c5.xlarge | $140/mo |

### Criteria Used

- CPU avg <40% over 14 days -> downsize candidate
- Memory avg <50% over 14 days -> downsize candidate
- Excluded: ASG instances (handled by ASG sizing)

Reserved Instance Analysis

## Reserved Instance Coverage

### Current Coverage

| Service | On-Demand | Reserved | Coverage |
|---------|-----------|----------|----------|
| EC2 | $5,000 | $3,000 | 38% |
| RDS | $2,000 | $0 | 0% |
| ElastiCache | $500 | $500 | 50% |

### RI Recommendations

| Resource Type | Term | Payment | Monthly Savings | Break-even |
|---------------|------|---------|-----------------|------------|
| 10x m5.large | 1 year | No upfront | $350 | 0 months |
| db.r5.xlarge | 1 year | Partial | $180 | 4 months |

### RI Purchase Criteria

- Stable workload for >80% of term
- Usage predictable for commitment period
- Consider convertible RIs for flexibility

Idle Resource Detection

## Idle Resources

### Unattached EBS Volumes

| Volume ID | Size | Cost/Month | Last Attached |
|-----------|------|------------|---------------|
| vol-xxx | 100GB | $10 | 90 days ago |
| vol-yyy | 500GB | $50 | Never |

### Unused Elastic IPs

| IP | Allocation ID | Associated | Cost/Month |
|----|---------------|------------|------------|
| x.x.x.x | eipalloc-xxx | No | $3.60 |

### Idle Load Balancers

| LB Name | Target Groups | Requests/Day | Cost/Month |
|---------|---------------|--------------|------------|
| old-api | 0 | 0 | $16.50 |

Phase 4: Risk Assessment

Optimization Risk Matrix

Risk Assessment Checklist

• Rollback plan documented
• Performance baseline captured
• Monitoring in place
• Stakeholders informed
• Timeline appropriate (not during peak)

Phase 5: Implementation

Implementation Priority

Implementation Checklist

• Change request approved
• Scheduled during low-traffic period
• Rollback plan ready
• Monitoring dashboards open
• Communication sent to stakeholders

Phase 6: Monitoring

Savings Tracking

## Savings Report

**Period:** [Month YYYY]
**Target Savings:** $X,XXX
**Actual Savings:** $X,XXX
**Achievement:** XX%

### Savings by Category

| Category | Target | Actual | Status |
|----------|--------|--------|--------|
| Rightsizing | $500 | $450 | 90% |
| Reserved Instances | $2,000 | $2,100 | 105% |
| Idle Resources | $200 | $200 | 100% |

### Monthly Trend

| Month | Spend | Savings | Cumulative |
|-------|-------|---------|------------|
| Jan | $50,000 | $0 | $0 |
| Feb | $48,000 | $2,000 | $2,000 |
| Mar | $47,500 | $2,500 | $4,500 |

Anti-Rationalization Table

Pressure Resistance

Dispatch Specialist

For cost optimization tasks, dispatch:

Task tool:
  subagent_type: "ring:cloud-cost-optimizer"
  model: "opus"
  prompt: |
    COST ANALYSIS REQUEST
    Scope: [accounts/services to analyze]
    Period: [time range]
    Focus: [rightsizing/RI/general optimization]
    Constraints: [budget targets, risk tolerance]