Alex K.

I build and ship React Native apps to the App Store and Google Play. Most recently: a golf-booking app with ~100k monthly active users at peak season, Apple Pay / Google Pay checkout and 50+ production releases behind it. 10 years in React Native, 15+ in software overall, 100% Job Success on Upwork. Greenfield builds, legacy rewrites, payments, custom native modules and CI/CD, in bare React Native or Expo, whichever your project already runs on. I use Claude Code every day, and every change is tested on a device and reviewed by me before it ships. Most recent engagement: 📱 5 years (2021–2026) as the mobile developer of Sweetspot's core product team, a production golf-booking app used across Europe and North America: • Rebuilt the app from legacy JavaScript to TypeScript on current React Native, with the old app live until the cut-over so sales never paused • Built the Adyen payment layer while Adyen's React Native SDK was still in beta: our own Swift and Kotlin bridges (card form, 3D Secure, Apple Pay / Google Pay), later replaced by the official SDK. 30k+ paid bookings a month, plus recurring card-on-file billing for memberships • Built geofenced arrival check-in with iOS Live Activities and the Android equivalent: 500k+ check-ins in a year • Owned the release pipeline: 50+ store releases via GitHub Actions + Fastlane, gated by Maestro E2E tests • Built a second app solo on Expo (SDK 56, Expo Router), from a SwiftUI prototype to public App Store and Google Play release in under two months How I can help you: ✔️ Build an app from scratch and publish to the stores ✔️ Add features to an existing app, or rewrite a legacy one ✔️ Integrate payments (Adyen, Stripe, Braintree, Apple/Google Pay) ✔️ Write custom native modules (Swift / Kotlin) ✔️ Ship iOS Live Activities, widgets and push-driven real-time features ✔️ Fix bugs, improve performance and stability ✔️ Set up CI/CD (GitHub Actions, Fastlane, semantic-release, Maestro E2E) Core stack: React Native (bare & Expo), New Architecture, Hermes, TypeScript, Swift/Obj-C, Kotlin/Java, Zustand, TanStack Query, React Navigation / Expo Router, Reanimated, Adyen, Firebase, Amplitude, REST/GraphQL, Jest & Maestro (E2E), GitHub Actions, Fastlane, semantic-release. Available for new projects. Message me to discuss yours.