How do you handle different React Native versions and what's the upgrade path (`react-native upgrade`, Upgrade Helper)?

React Native upgrades are not a simple npm update — versions touch native files (Podfile, build.gradle, AppDelegate, MainApplication). The tooling has gotten much better, but you still need a deliberate process.

The Upgrade Helper (the canonical tool):

• Web tool at react-native-community.github.io/upgrade-helper.

• Shows a file-by-file diff between your current RN version and any target version.

• You manually apply changes to ios/, android/, package.json, babel.config.js, etc.

The CLI upgrade command:

• npx @react-native-community/cli upgrade [version] — runs the same diffs and three-way merges them; conflicts marked for manual resolution.

• Always works best on a clean git tree so you can review and reset.

For Expo projects (simpler):

• npx expo install expo@<new-sdk> then npx expo install --fix to update peer deps to compatible versions.

• npx expo prebuild --clean regenerates ios/ and android/ from app.json for that SDK.

• Read Expo's SDK changelog for breaking changes per release.

Best practices:

• Upgrade on a dedicated branch with empty diff (commit clean before starting).

• Don't skip more than 2-3 minor versions at once — go incrementally.

• Audit each native module's New-Arch compatibility on every major bump.

• Always do a full E2E run on real devices after the upgrade.