Hire the Best iOS Developers
in Vietnam

A client in the US shipped a Bluetooth device halfway around the world, all the way to me here in Vietnam. Then he waited three weeks for it to arrive. He could have hired someone much closer to home. He chose to wait for me instead. That story tells you what I actually do. Anyone can build a mobile app. The hard part is making the app work with a real physical device, and keeping it connected when you switch to another app, the signal gets weak, or the battery runs low. That's where most projects quietly fail. It's also why my client didn't want the nearby option. He wanted someone who would get the device right, and built the app right. Over 17,000 hours on Upwork and 70+ clients, I've built apps for all kinds of devices: a heart monitor used in healthcare, car alarm and remote-start systems, a tap-to-pay card reader, a skydiving altimeter, Bluetooth printers, and smart scales. I even keep a shelf of the small electronic boards these devices run on. But the device is only half the job. To deliver the whole product, I work across every major mobile toolset: Flutter, iOS, Android, and React Native. I pick the right one for your project, or match the app you already have. So one person handles the app, the connection to your device, and getting it approved on the App Store and Google Play. Not three separate hires. Recently, I'm now Anthropic-certified in building with Claude, and it would benefit you if we go together. Claude handles the repetitive coding work, so you need a smaller team (one senior developer now covers what used to take several) and launch sooner & monetize quicker. One past client said it better than I can: 🗣️ "Hau demonstrated excellent knowledge and skill in completing the project and produced high quality outcomes. The project involved a complicated architecture with both cloud and hardware connections which Hau was able to handle well." Google Certified Android Developer · Anthropic Claude Certified · Upwork Top Rated Plus (top 3% of freelancers, 100% Job Success) If you have a device that needs an app, or an app that needs to go live, send me a message and let's talk. 🕛 I'm in ICT (UTC+7️⃣), but can work in any time zone.

I'm a Senior Mobile Developer with 10+ years of experience building high-quality iOS and Android apps, both native and cross-platform. I help businesses and startups turn their ideas into fast, reliable, and user-friendly mobile applications. Whether you're starting from scratch or need someone to fix bugs, improve performance, or maintain an existing app — I'm here to help. ✅ My core strengths: React Native & Flutter – Cross-platform apps that run smoothly on both iOS and Android. Swift & Objective-C – Native iOS development with deep platform knowledge. Kotlin & Java – Robust native Android applications. Bug fixing & troubleshooting – Quickly identify and resolve issues in existing codebases. Performance optimization – Make your app faster, lighter, and smoother. I focus on writing clean, maintainable code and delivering solutions that work — not just on day one, but long term. If you're looking for a reliable mobile developer to help you build or improve your app, let’s talk!

Building smart contracts on EVM and Near. Over 8 years of experience in the development, deployment, and test environment of applications for mobile platforms. Over 300 projects have been done since 2010 to present. I always support the best quality and fast speed to my customer. I promise the following services for my employer : - Highest quality. - Fast Speed. - Best Communication for every day. - After Service Top Skills: ▪ Rust/Truffle/Ethers.js ▪ NestJs, NextJs, Prisma, PostgreSQL ▪ iOS/Android SDK. ▪ Flutter Crossplatform ▪ Mobile App design using Sketch App ▪ Node.js, Django, REST Framework, Flask, Celery. ▪ GraphQL, REST, gRPC. ▪ Postgres, MySQL, MongoDB. ▪ RabbitMQ, Redis, Memcached. Chat now for more detail. I am available 40-50 hours per week.

Senior iOS Developer with 8+ years of hands-on experience building, maintaining, and scaling high-quality iOS applications using Swift, SwiftUI, UIKit, and Objective-C. I specialize in developing production-ready mobile apps with clean architecture, smooth user experience, and reliable performance. I have strong experience with Firebase, Firestore, Cloud Functions, REST APIs, in-app purchases, subscriptions, Apple Sign In, push notifications, Core Data, Realm, widgets, BLE, and App Store release workflows. In addition to native iOS development, I also have experience working with Chromium-based projects, WKWebView-heavy applications, browser-style features, custom web-to-native integrations, JavaScript bridge communication, deep links, and hybrid app flows. This allows me to handle complex projects that combine native iOS performance with embedded web/browser functionality. I can help you with: - Building iOS apps from scratch using SwiftUI or UIKit - Refactoring and improving existing iOS codebases - Fixing complex bugs and performance issues - Firebase, Firestore, Authentication, Cloud Functions, and Push Notifications - In-app purchases, subscriptions, and payment-related flows - REST API integration and real-time data synchronization - Core Data, Realm, offline storage, and local caching - Chromium-based features, WKWebView, JavaScript bridge, and hybrid app flows - BLE, Apple Sign In, widgets, and native iOS features - TestFlight, App Store submission, and production release support - UI polishing based on Figma or existing designs I focus on writing clean, maintainable, and scalable code. My goal is not only to complete tasks, but also to help clients build stable, user-friendly, and production-ready iOS applications. If you are looking for a reliable iOS developer who can understand requirements quickly, communicate clearly, and deliver high-quality work, I would be happy to help with your project.

Over 7 years of experience building mobile apps for iOS and Android, from first concept to a live listing on the App Store and Google Play. I work fluently in both native languages (Swift, SwiftUI, Java, Kotlin, Jetpack Compose) and cross-platform frameworks (React Native, Flutter), so I can recommend the right approach for your product instead of forcing one stack onto every problem. That broad experience helps clients make the call that fits their goals. Should you use React Native or Flutter to ship faster and lower cost? Should you go native for maximum performance and the latest platform features? Those are exactly the trade-offs I help you weigh before a line of code is written. I don't just build to a spec, I help define it. I can join at any stage of the app lifecycle: clarifying requirements, UX and architecture decisions, development, testing, release, and post-launch iteration. I've taken apps through the full App Store and Google Play submission and review process many times and can guide you through it smoothly. WHAT I BRING + Platforms: iOS (iPhone, iPad), Android (phone, tablet) + Native: Swift, SwiftUI, UIKit, Objective-C basics, Java, Kotlin, Jetpack Compose + Cross-platform: React Native, Flutter (Dart), Expo + Languages: Swift, Kotlin, Java, JavaScript, TypeScript, Dart + Backend & data: RESTful and GraphQL APIs, Firebase, real-time sync, offline-first data, local storage (SQLite, Realm, Core Data) + Common features: Google/Apple Maps, geolocation, push notifications (FCM, APNs), in-app purchases, subscriptions, Stripe and payment integrations, social login, camera and media + Architecture: MVVM, MVC, Clean Architecture, state management (Redux, Provider, Bloc) + Quality: unit and UI testing, high code coverage, debugging and crash reporting (Crashlytics, Sentry) + Performance: optimizing battery, smoothness (60fps UI), memory, and network usage + Release & DevOps: App Store and Google Play submission, TestFlight, Fastlane, CI/CD for mobile (GitHub Actions, Bitrise) + Tools: Xcode, Android Studio, VS Code, Git Whether you need a new app built from scratch, an existing one improved and stabilized, or advice on the best technical path forward, I'd be glad to help you ship something users actually enjoy.

With over 10 years of hands-on experience in mobile development and full-stack engineering, I build robust, scalable, and user-centric applications that deliver real business impact. Now, as an Agentic Engineer, I’ve leveled up my practice by mastering advanced AI agent systems and autonomous coding workflows. I design, orchestrate, and deploy intelligent agent teams that dramatically accelerate development — from rapid prototyping to production-grade solutions. Using agent coding paradigms, I can replicate and extend capabilities similar to Cursor, Claude Code, and Codex: building custom plugins, skills, sub-agents, multi-agent orchestrators, and even managing controlled “agent chaos” for complex problem-solving. What I Deliver: - AI-Powered Development: Autonomous agents that plan, document, write, review, debug, and iterate code at superhuman speed while maintaining architectural excellence. The importance is with my experience I can control, review the chaos and quality - Automatic Workflow with n8n platform - Agent Ecosystems: Custom agent teams, orchestrators, memory systems, and tool-use frameworks tailored to your project needs. - Full-Stack + Mobile Mastery: Production-grade mobile apps (iOS/Android), web platforms, and backend systems enhanced with AI intelligence. - Accelerated Delivery: Significantly reduced development time and costs while increasing innovation and code quality. - Claude code: creating plugins, skills, MCPs, sub agents, agent team, gastown, GSD,... Whether you need a next-generation mobile product, an AI-augmented internal tool, a custom agent platform, or to 10x your existing development velocity — I combine deep traditional engineering expertise with cutting-edge agentic capabilities to turn ambitious ideas into reality faster than ever. Let’s build the future — intelligently, autonomously, and at scale.