Challenge
One Sudoku started as a classic Sudoku game and needed to grow into a product that could live on both iOS and Android. The goal was to keep the simple, calm gameplay experience while adding the features people expect from a modern mobile game: accounts, cloud sync, daily challenges, statistics, leaderboards and notifications.
The challenge was to do this from one shared codebase without letting the network get in the way of the game itself. Players had to be able to open the app and start a puzzle immediately, with no account and no internet connection, and still have their progress kept safe once they chose to sign in.
Solution
I rebuilt One Sudoku from the ground up with React Native and Expo, using a local-first architecture where every gameplay path works offline and the backend is an addition rather than a requirement.
My contributions included:
- Building a single cross-platform codebase with Expo SDK 57, React Native 0.86 (New Architecture, Hermes) and strict TypeScript.
- Designing a local-first data layer: puzzles come from a bundled, pre-verified pool, and every write lands in MMKV storage before it is queued for upload.
- Implementing four difficulty levels, a Daily Challenge, streaks, detailed statistics and leaderboards.
- Integrating Firebase for authentication (Google, Apple, Email and Guest), Firestore cloud sync, Analytics, Crashlytics and push notifications.
- Adding Google AdMob in a way that stays out of active gameplay, plus an optional Premium subscription through RevenueCat.
- Creating a smooth, polished interface with Skia and Reanimated.
- Setting up release pipelines with EAS Build and EAS Submit, and publishing the app on the App Store and Google Play.
The result is a fast, calm Sudoku experience that works anywhere, even offline, while giving signed-in players cloud-backed progress, daily goals and a reason to come back every day.