Cost Impact Review

Use this skill when the main risk is unit economics or infra cost regression, not correctness.

Trigger Conditions

Use this skill when:

• a change adds new database queries, API calls, or background work that may scale per-request
• caching, batching, or pagination behavior is changing
• third-party SaaS or paid API usage may grow
• log, trace, or metric volume may increase noticeably
• the team wants a cost regression check before release

Do not use this skill for license/compliance review or for performance investigation of an existing slowdown.

Workflow

1. Identify the change and the cost drivers it touches.
2. Estimate cost direction: per-request, per-user, per-event, or per-deploy.
3. Compare with cheaper alternatives (caching, batching, lazy paths).
4. Flag risk hotspots that scale with traffic.
5. Recommend smallest mitigations or a measurement plan.
6. Suggest verification once rollout begins.

Output

For non-trivial work, provide:

• affected cost drivers
• likely cost direction and rough magnitude
• risk hotspots
• recommended optimizations or guards
• verification plan

Coordination

After cost review:

• use architecture-refactor-guidance if a structural change is the right mitigation
• use release-rollout-strategy to add cost-aware checkpoints
• use ship-readiness if cost risk is the last release blocker

Invocation Examples

• "Use cost-impact-review from dev-workflow-kit to check whether this change increases infra or per-request cost."
• "Use cost-impact-review to estimate whether this new third-party call will materially raise our bill."
• "Use cost-impact-review before release because the new query might run on every page load."