Hai N.

I am a Senior Mobile Application Developer with 10+ years of experience building, maintaining, and improving production-ready mobile applications across Android, iOS, Flutter, and React Native. My strongest expertise is Android development with Java and Kotlin , with extensive experience in mobile architecture, performance optimization, API integration, and complex application features. I also have strong hands-on experience with Flutter and cross-platform mobile development, allowing me to work effectively on both native and cross-platform projects. I specialize in helping businesses build new mobile applications, improve existing apps, fix complex issues, and integrate third-party services and APIs. What I can help you with 🔹 Native Mobile Development * Android — Java, Kotlin, Android SDK * iOS — Swift * Native UI, system components, background processing, notifications * Performance optimization and memory management 🔹 Cross-Platform Development * Flutter / Dart * React Native * Cross-platform architecture and reusable components * State management and scalable application structure 🔹 Mobile App Development & Maintenance * New feature development * Existing app improvements * Bug fixing and troubleshooting * Performance optimization * UI/UX implementation from Figma designs * App modernization and codebase refactoring * Android/iOS build and release support 🔹 Architecture & Code Quality * Clean Architecture * MVVM / MVP * SOLID principles * Kotlin Coroutines & Flow / StateFlow * Dependency Injection with Hilt * Room / SQLite * Firebase * REST APIs and JSON 🔹 API & Third-Party Integrations * RESTful APIs * Firebase Authentication / Firestore * Push Notifications * RevenueCat / In-App Purchases * Payment and subscription systems * Social login * Analytics and crash reporting * Third-party SDK integration * AI API integration * Enterprise backend integration I have experience working on mobile applications throughout the full development lifecycle — from architecture and implementation to debugging, optimization, testing, and production release. After several years as a hands-on developer, I became a Team Leader, where I was responsible for technical architecture, development standards, code reviews, technical decisions, and mentoring developers. Whether you need someone to build a mobile app from scratch or take over and improve an existing codebase, I can help analyze the current implementation, identify technical issues, and deliver a maintainable solution. Core Technologies: Android | Kotlin | Java | Android SDK | iOS | Swift | Flutter | Dart | React Native | Firebase | REST API | SQLite | Room | Clean Architecture | MVVM | MVP | Git