Full Stack Software Engineer
NightbornBrussels, BelgiumFeb 2025 - Present
Build React Native and React/TypeScript features for 6+ clients, from architecture to production, and support junior developers through code review and pair programming.
Golden Palace CasinoReact Native app (iOS & Android, fintech)
- Shipped 30+ production features in a React Native fintech app (~30k active users): multiple payment providers and identity/bank-compliance checks with camera document and card scanning, geolocation, and biometric login.
- Resolved complex interaction conflicts between React Native Gesture Handler and a WebView with an interactive canvas, implementing a native module wrapper around the WebView to intercept and control touch events between the native and web contexts.
- Doubled UI rendering performance on low-end devices, from under 30 to a stable 60 FPS, through render-tree profiling, list virtualization and memoization.
- Reduced app startup time by 78%, from 4.1s to 0.9s, by enabling Hermes and restructuring the lazy-loading strategy for non-essential screens.
- Spotted that regressions were slipping past QA into production on the critical flows. Closed the gap with a Maestro E2E suite, scenarios mapped with the PM, running per-PR, nightly and pre-build: 15+ bugs caught before release, zero regressions on those flows since.
- Improved the whole team's development experience by cutting mobile build time by ~85%, from 35 to under 5 minutes, with a build-caching system.
Press Shop & MoreReact Native loyalty app and the backend behind it
- Built the first version of the app: 20+ flows covering auth, payments, KYC and loyalty. Helped define the Clean Architecture structure and the design system that later features were built on.
- Implemented the full identity stack : Firebase Auth (tokens, refresh, email verification) plus itsme, Belgium's national digital ID, for KYC. Regulated fintech, so this had to be right before anything else shipped.
- Push notifications with Firebase Cloud Messaging, including the backend side: device token registration, storage, lifecycle.
- Enabled payments end to end by integrating several payment gateways in the backend and covering the correctness and security of each transaction path.
- Set up the quality gates for both the mobile and backend repos: linters, cyclomatic complexity checks, unit and integration tests with 80% coverage enforced, plus an E2E suite. Nothing merges without passing them.
- Wrapped the client's loyalty-points API as a gateway in our backend so the app only ever talks to one contract. When the third-party changes, mobile doesn't break.
- Built the QA release pipeline that distributes test builds to TestFlight and Firebase App Distribution automatically, cutting build time by ~80% with a cache system and Expo repack.
Stack
React NativeExpoExpo Native ModulesTypeScriptSwiftUIKotlinTanStack QueryFirebase Cloud MessagingFirebase AuthFirebase CrashlyticsGraphQLNode.jsExpressPostgreSQLKysely Query BuilderOnion ArchitectureMaestroSentryFastlaneGitHub Actions CI/CD