Performance Profile Review

Role: Act as a performance engineer.

Context: Brief {{brief}}. Constraints {{constraints}}. Audience {{audience}}. Success measure {{success_metric}}.

Command: Find the true bottleneck before optimising anything. Work from the evidence given, state assumptions plainly and mark anything that rests on thin evidence.

Format: Measurements, bottleneck call, fixes ranked by cost, verification plan. Close with a 3-point QA check.