I build the mobile apps people open every day, down to the native code.

Students watch courses on the Kiwify app, so playback is the core of the product. I led a custom native player end to end, from planning to release.

• Built on ExoPlayer on Android and AVFoundation on iOS, bridged into the Flutter app.
• Quality selection, and a warm-up of the next lesson so it starts faster.
• Chromecast and AirPlay, picture-in-picture and background audio.
• A data-saving mode for students on mobile networks.
• Released gradually through remote config: I controlled which users got the new player and widened access as it proved stable.

Kotlin, ExoPlayer, Swift, AVFoundation, Flutter

A payments account on a phone has to prove that each request comes from the real device and the real person. I created the app's security SDK in Swift and Kotlin.

• Hardware-backed device registration with App Attest and Play Integrity.
• Proof-of-possession signing on API requests.
• Biometric-protected secure storage and emulator detection.
• On-device key-pair generation for API keys and service accounts.

Swift, Kotlin, React Native, TypeScript

I designed and built a server-driven UI engine so product teams can publish new screens through remote config, without waiting for a store release.

• Schema validation and versioning, so an old app never receives a screen it can't render.
• A rules engine for showing the right screen to the right user.
• A generated component catalog that product teams build from.

React Native, TypeScript, Expo

The app serves sellers managing sales and payouts and students watching courses. Over four years I worked on it, more than three as its only mobile engineer, while its users grew from 300k to more than 1.5M.

• About 4,700 commits, around 75% of the codebase history, and 140+ store releases.
• Built the testing culture from scratch: 800+ test files, full-app integration tests and coverage on every pull request.
• Led the incremental move from a monolith to Clean Architecture feature packages while a growing team shipped in the same codebase.
• Took the app international in English, Spanish and Portuguese, and added observability, feature flags and remote rollback.

Flutter, Dart, Swift, Kotlin, Datadog, Codemagic