sairam0424 Skill — Cost Estimation
When this skill activates
Any task involving cloud cost modeling, FinOps, instance strategy selection, cost forecasting, per-request cost analysis, right-sizing, or cost allocation.
Mandatory actions when this skill is active
Before writing any code
- Estimate costs BEFORE building: compute + storage + network + managed services.
- Identify cost-dominant components (usually storage or network egress).
- Define budget constraints and alerting thresholds.
During implementation
- Choose instances based on workload profile (compute/memory/IO bound).
- Implement resource tagging for cost allocation from day one.
- Use auto-scaling with min/max bounds.
- Prefer managed services when ops cost exceeds infrastructure savings.
After implementation
- Set cost alerts at 50%, 80%, 100% of budget.
- Create per-service cost dashboard.
- Schedule monthly cost review for drift and optimization.
FinOps Phases
- Inform: tag all resources, build dashboards, implement showback/chargeback.
- Optimize: right-size, reserve steady workloads, spot for batch, eliminate waste.
- Operate: automate (scheduled scaling, auto-stop dev), embed cost in PR review.
Cost Modeling
Monthly = Compute + Storage + Network + Managed + Support
Compute: instances * hours * $/hour
Storage: GB * $/GB + IOPS * $/IOP
Network: GB egress * $/GB (ingress usually free)
Cost/Request: total_monthly / total_requests
Instance Strategy
| Type | Discount | Use For | Never For |
|---|---|---|---|
| On-Demand | 0% | Variable, dev, testing | Steady production (wasteful) |
| Reserved (1-3yr) | 30-72% | Steady production (>70% util for 6+ months) | Uncertain workloads |
| Spot/Preemptible | 60-90% | Batch, CI/CD, fault-tolerant workers | Databases, user-facing |
Right-Sizing Indicators
- CPU < 40% consistently = oversized.
- Memory < 50% consistently = oversized.
- Process: collect 2-4 weeks metrics → find binding constraint → resize to peak + 20%.
Cost Allocation Tags (Minimum)
team,service,environment,cost-center.- Optional:
featurefor per-feature attribution. - Shared infra: divide proportionally by request count or CPU time.
Forecasting
Next Month = Current * (1 + organic_growth) + planned_launch_impact
- Inputs: historical trend (3-6 months), planned launches, seasonal patterns.
- Weekly: check for anomalies. Monthly: forecast vs actual. Quarterly: re-evaluate commitments.
Self-check before task completion
- Did I estimate costs before proposing infrastructure?
- Are resources tagged for cost allocation?
- Is instance strategy appropriate (on-demand vs reserved vs spot)?
- Are cost alerts configured at budget thresholds?
- Is right-sizing based on actual utilization data?
- Is there a cost visibility mechanism (dashboard)?
- Are managed-vs-self-hosted trade-offs documented?