Payments, offline-first systems and device-level integrations — built to production standards, proven with real money at scale.
Android (Kotlin), iOS (Swift), React Native and Kotlin Multiplatform. I build apps that hold up under real usage — clean architecture, testable code, and performance budgets that survive contact with production.
Stripe Terminal, Tap-to-Pay, RFID and offline-first transaction architecture. I've shipped multi-terminal POS processing real money at live events — where a dropped transaction is a lost sale, not a log line.
Offline queuing, sync engines, conflict resolution and fault-tolerant systems. Designed for venues, kiosks and field environments where connectivity is intermittent and correctness is non-negotiable.
BLE, RFID, serial/UART, kiosk systems, SUNMI devices and barcode scanners. Deep experience with the device-level work — SDK quirks, firmware handshakes and the edge cases that only appear on real hardware.
Node.js, NestJS and REST APIs. Backends designed to be the reliable spine of a mobile product — clear contracts, observability, and architecture that scales with the client apps it serves.
Kotlin Multiplatform and React Native. Share the business logic that matters — models, validation, networking — while keeping platform-native UI and performance where users feel it.
Reach out to discuss your project. I typically respond within 24 hours.