05 / NATIVE SYSTEMS

Closer to the metal.

Under the interface, down to the details.

I work on React Native libraries at Margelo, including NitroSQLite and NitroFetch. I like building the pieces that other engineers can use in their own apps.

NitroSQLite brings fast local storage through Nitro Modules. I’ve also worked on moving Expensify’s Onyx storage onto it, so this library work has been tested against a large production app.

I integrated NitroFetch into Expensify’s native app and added prefetching for a critical startup request. That lets the request begin while the JavaScript bundle loads. I wrote a detailed post about the integration and the performance results on Margelo’s blog.

In that rollout, I measured 15–30% shorter average request durations and a critical startup request that completed more than 200 ms sooner.

I also built expo-native-variants. It generates development, preview, and production app variants in one Expo prebuild, so I can choose the app I need in Xcode or Android Studio without keeping generated native folders in Git.

• Explore react-native-nitro-sqlite
• Read the NitroFetch story
• Explore expo-native-variants