Full-stack and mobile developer specializing in real-time systems, payment infrastructure, and production-grade applications across iOS, Android, and web. Based in Vietnam, working with international clients since 2008. What I build best: → Mobile applications — iOS (Swift/SwiftUI), Android (Kotlin), and cross-platform (React Native, Flutter). I've shipped 80+ mobile and web apps since 2008, ranging from lightweight utility apps to complex platforms with real-time sync, biometric authentication, and payment processing. App Store and Google Play submission, TestFlight workflows, and post-launch support are all part of my delivery. → Real-time platforms — live dashboards, multiplayer systems, WebSocket-driven applications where every millisecond of sync matters. I've shipped production systems handling concurrent users with state machines, escrow logic, and recoverable execution flows. → Payment & fintech infrastructure — multi-provider payment gateways, commission tracking, subscription billing, and secure transaction pipelines. Experience spans both traditional payment processors and blockchain-based settlement (Solana, multi-chain EVM). → Full-stack web applications — from MVP to production. My core stack is Next.js, Node.js, PostgreSQL, and Supabase, with Redis for caching and real-time layers. I build clean APIs, admin dashboards with role-based access, and responsive frontends that ship fast. → Blockchain & Web3 — Solana smart contracts (Anchor/Rust), on-chain escrow systems, token economics, and dApp frontends. I've built and deployed multiple Solana mainnet applications including gaming platforms and crypto-to-fiat payment services. → Hardware & IoT integration — currently developing a medical device (electrotherapy system) with STM32 microcontroller, FDA compliance pathway, and a companion web dashboard for clinicians. Technical stack: Swift · SwiftUI · Kotlin · React Native · Flutter · Next.js · React · TypeScript · Node.js · PostgreSQL · Supabase · Firebase · Redis · [login to view URL] · Solana (Anchor/Rust) · Docker · AWS · Python How I work: I deliver production code, not prototypes. Every project ships with documentation, deployment scripts, and a clean handover. I communicate directly — you'll get honest timelines, early flags on scope issues, and no surprises at delivery. I'm comfortable working autonomously or plugging into an existing team. 80+ applications shipped across iOS, Android, and web since 2008. Currently focused on fewer, higher-quality engagements.