uphold

Autonomous, scientific React Native & Expo performance optimization via a propose -> measure -> keep/revert loop. Use this WHENEVER an RN/Expo app is slow, laggy, janky, stuttering, freezing, or memory-hungry — slow cold start / TTI, dropped frames while scrolling a FlatList/SectionList/FlashList, rising RAM or a suspected memory leak, a bloated JS bundle, or wasted/excessive re-renders — even if the user never says "metrognome" or the word "performance". Also use it to build an interactive 3D Perf Map of an RN repo, profile a specific screen or component, or surface the worst perf offenders. It measures every change N times on a real device/simulator and keeps a fix only if the gain beats the measurement noise, committing each win with git-as-memory. Scope is React Native / Expo (Metro + Hermes) only — for web, Next.js, or Core Web Vitals work, use a web performance skill instead.