React Native Performance & Build

Degree of freedom: MIXED. Which category and fix [HIGH freedom]; measure before/after, 16KB alignment, and upgrade-helper diffs [LOW freedom — run exactly].

The performance, bundling, and upgrade layer for React Native / Expo. mobile-rn-screen handles screen layout and native feel; this skill handles speed, size, and version moves.

Distilled from Callstack's React Native best-practices skill (MIT) and the Ultimate Guide to RN Optimization.

How to reason

1. Measure — RN perf monitor / profiler numbers first
2. Category — FPS, bundle, TTI, native, memory, or animation
3. Fix — the profiled hotspot only
4. Re-measure — before/after on a real low-end device

Worked example