Optimizing Hermes Bytecode Bundle Size and SourceMap Handling in React Native
To counter the 40‑100 % size increase of Hermes bytecode bundles after upgrading to React Native 0.70, the team switched to xz compression (cutting zip size 20‑26 %), enabled hermesc ‑O optimization (shrinking bundles 10‑22 % while requiring a two‑step source‑map merge), and used the ‑base‑bytecode option with bsdiff to reduce incremental OTA patches by up to 85 %, collectively improving download and update efficiency.