skills/vibe-reliability/references/performance-budget-polish.md

# Performance Budget Polish

## Operation

Implement the requested coherent change at the owning source and update directly affected consumers. An earlier audit is optional when the user and repository already establish the target. Validate the changed behavior, then stop when the requested scope is complete.

## Goal

Implement one selected, evidence-backed Performance Budget improvement at the authoritative owner. Complete the directly affected contract without broad cleanup or redesign.

## Domain rules

- Optimize the dominant owner and preserve end-to-end deadlines, cancellation, fairness, and failure semantics.
- Add bounded admission/backpressure before increasing concurrency or cache complexity.
- Keep measurement cheap, stable, and representative; avoid high-cardinality or per-request heavy telemetry.
- Update performance tests/budgets/docs/alerts only where the measured contract changed.

## Validation

- Re-run the same workload and report before/after distributions, resource use, and variance.
- Run correctness/failure tests for changed caching, batching, concurrency, or query behavior.
- State production topology/traffic/hardware assumptions not proven.