Find performance issues with a measured baseline. Do not invent SLOs or impact percentages. Report-only unless the user asked to implement. 1. Read testing docs for budgets if present. Capture a baseline with the repo profiler, traces, tests, or job timing — not estimates. 2. Locate the owning hot path (query, render, allocation) with that evidence. 3. Recommend the smallest change. Implement only when authorized. Re-measure after a change. 4. If a new budget is required, document it in existing testing docs instead of inventing an SLO here. 5. Docs: if behavior or commands changed.