Hire the Best NFC Professionals

I build enterprise software that holds up under real pressure — 400,000+ daily transactions, 130+ live POS terminals, and 30+ deployed sites are running on systems I've architected and shipped. With 6+ years in .NET (Core, Framework, 6/7/8), Flutter, and SQL Server, I specialise in: ✅ High-volume backend systems & RESTful API development (ASP.NET Core) ✅ RFID-based cashless payment ecosystems (NFC, OCR, industrial RFID) ✅ Complex SQL Server design — stored procedures, indexing, query optimisation ✅ Flutter / Dart mobile applications with real-time API integration ✅ WPF / WinForms desktop applications ✅ Industrial automation — Siemens PLC, serial communication, conveyor tracking ✅ CI/CD pipelines — Azure DevOps, GitHub Actions, IIS deployment ✅ Technical leadership — code reviews, mentoring, architecture decisions One concrete result: I cut transaction processing time from ~2,500ms to under 900ms — a ~30% performance improvement across a live, high-throughput payment system. I work directly with clients to gather requirements and translate them into clean, documented, production-ready code. I'm comfortable managing full delivery cycles: architecture → development → deployment → client handoff. If you need a senior engineer who owns the outcome — not just the ticket — let's talk.

✅ 12+ Years in Mobile Development 🏆 Top Rated | Kotlin, iOS, SDKs, BLE, VoIP & System-Level Android Apps I help businesses build stable, production-ready Android/iOS applications designed for long-term reliability, scalability, and real-world usage. Over the last 12+ years, I’ve worked on Android/iOS apps ranging from consumer products to enterprise systems, including VoIP platforms, Android SDKs, BLE integrations, location tracking systems, streaming apps, and custom Android OS-level features. My focus is building and maintaining Android/iOS systems that remain stable, maintainable, and performant over time. 🚀 What I can help you with: ✅ Native Mobile App Development (Kotlin & iOS) ✅ Android SDK Development & Integration ✅ BLE (Bluetooth Low Energy) Applications ✅ VoIP, Audio/Video Calling & Streaming Apps ✅ Background Services & Foreground Services ✅ Existing App Maintenance & Bug Fixing ✅ Play Store Release & Compliance ✅ Performance Optimization & Stability Improvements ✅ Custom Android OS / System-Level Features ✅ Long-Term Product Development & Support ⚙️ Core Android Expertise: ✔ Jetpack Compose & Modern Android Architecture ✔ MVVM, Clean Architecture & Modular Codebases ✔ Firebase, Firestore & Realtime Systems ✔ REST APIs, WebSockets & SignalR ✔ Google Maps & Real-Time Location Tracking ✔ Media Streaming & Real-Time Communication ✔ Offline Storage & Sync Solutions ✔ Push Notifications & Background Processing ✔ In-App Purchases & Subscription Systems ✔ Kiosk Mode & Device Management 🔥 Specialized Experience: ✔ Android SDK development used across multiple applications ✔ BLE communication & external device integrations ✔ WebRTC, Twilio & Linphone integrations ✔ Enterprise Android systems with long-term maintenance ✔ Performance-critical and reliability-focused Android apps 🏢 Some Projects & Domains Worked On: ✔ Spirit Airlines ✔ Santander UK ✔ Plickers ✔ Ringplan VoIP ✔ Tracking & Logistics Applications ✔ Enterprise Cargo & Retail Systems I personally oversee projects from architecture to final delivery. For larger engagements, I collaborate with my in-house team of 25+ developers across Android, iOS, Flutter, backend, QA, web, and DevOps - giving clients a single point of contact backed by complete execution support. If you're building a new Android/iOS product, scaling an existing app, or solving complex Android/iOS issues, feel free to message me. Happy to review your app or requirements before we start.

I am a Full Stack Web & Mobile App Developer with expertise in Web Development, iOS & Android App Development (Top 3%), maintaining 100% Client Satisfaction on Upwork and successfully delivering hundreds of projects across industries. I am a Top-Rated Plus Mobile App Developer specializing in Flutter, React Native, iOS (Swift), Android (Kotlin) and Full-Stack Application Development. I build AI-powered mobile apps, real-time video streaming platforms, SaaS products, MVPs and on-demand service applications with scalable backend architectures using Node.js, NestJS, Laravel and Firebase. I have had the opportunity to work with numerous startups, scale-ups and enterprises, helping them design, develop, launch and scale high-performance mobile and web applications that work flawlessly across devices. ✅ I Can Help You With: - Mobile App Development with Web Admin Panel - MVP Development & SaaS Application Development - API Development & Third-Party Integrations - Node.js / NestJS Backend for Mobile & Web Apps - Laravel / PHP Backend Development - Firebase Integration (Auth, Firestore, Cloud Functions) - Payment Gateway Integration (Stripe, Razorpay, PayPal) - Real-Time Chat, Notifications & WebSocket Integration 💡 Having Expertise In: - AI-Powered Mobile Applications - Real-Time Video Streaming Apps - Live Streaming & Video Sharing Platforms - E-Learning & EdTech Applications - E-Commerce & Marketplace Apps - On-Demand Service Apps (Taxi, Food, Delivery, Booking) - Chat & Social Networking Apps - SaaS & Subscription-Based Platforms - Gamified Mobile Applications - AR/VR Mobile App Development - IoT & BLE-Based Mobile Applications 🎯Key Milestones: 🚀 Rewarded as 🏆 𝗧𝗢𝗣 𝗥𝗔𝗧𝗘𝗗 𝗣𝗟𝗨𝗦 🏆 by Upwork (𝗧𝗼𝗽 𝟯%) 🚀 7000+ personal hours on Upwork and still counting 🚀 100000+ agency hours on Upwork and still counting 🚀 100% Job Success (Client Satisfaction Ratio) 🚀 500+ jobs completed successfully as an Agency 🎯 Checkout my portfolio of apps on Upwork: Over the past decade, I have honed my skills in developing a diverse array of iPhone and Android applications Development ✅ Health and Fitness Apps ✅ GPS/ Geo Location Apps ✅ Trade Apps ✅ Homeowner/Contractor App ✅ Artificial Intelligence based Apps ✅ Bluetooth / BLE Integration Apps ✅ Food Delivery Apps ✅ Nutrition Planning Apps ✅ Restaurant Search Apps ✅ Salon Booking Apps ✅ Gym Booking Apps ✅ Taxi Apps ✅ AI Powered Apps ✅ E-commerce Apps ✅ Dating and TikTok Style Apps ✅ Video Streaming, Voice Calling, Chat and Messaging Apps ✅ Real Estate Apps ✅ Driver Instructor Finding Application ✅ Hotel and Travel Booking Apps ✅ E-Learning Mobile Application ✅ Wellness & Meditation Application ✅ NDI's Industry Applications 🎯 Areas of Expertise ◉ Mobile App Development: Swift, Objective C, Kotlin, Java, Jetpack ◉ Cross-Platform App Development: Flutter (Dart), React Native ◉ Backend Development: Node JS, Nest JS, Laravel, PHP, Express ◉ Frontend Development: React JS, Next JS, Angular, HTML5, CSS3 ◉ API Development & Integrations: REST APIs, AWS Lambda, API Gateway ◉ Databases & Cloud Storage: MySQL, MongoDB, Firebase, DynamoDB ◉ Real-Time App Features: Socket IO, Firebase Real Time Database, Twilio ◉ Payment Gateway Integration: Stripe, Razorpay, PayPal, Braintree ◉ Maps & Location Services: Google Maps, Apple Map Kit, GPS Tracking ◉ Version Control & Collaboration: GitHub, Bitbucket, GitLab I specialize in no-code/low-code development and AI integrations, allowing you to launch faster while keeping costs low without compromising quality. Additional Services that i am offering: - 6 Months Free Maintenance once the apps goes live on apple store and Google play store - Ownership/iP rights from the day one uploaded on the Client Github - Regular Updates & Scrum meetings. - Following Agile Scrum Methodology from day one - Strictly adhering to the Apple Guidelines and Google Guidelines. - Taking Complete responsibility of Deployment on both Apple store and Google Play store. I specialize in no-code/low-code development and AI integrations, allowing you to launch faster while keeping costs low without compromising quality. I work with tools like Bubble, FlutterFlow, Webflow and integrate powerful AI solutions using Claude, GPT and OpenAI APIs to build smart, automated systems. 🔹 What I Do - Full Stack Web & Mobile App Development - No-Code / Low-Code Development (Bubble, FlutterFlow, Webflow) - AI App Development & Integration (Claude AI, GPT-4/5, OpenAI API, Chatbots, Automation) - SaaS Application Development (Subscription Models, Multi-Tenant Systems) - API Integration (Payment gateways, third-party services) - Dashboard & Admin Panel Development - Workflow Automation (Zapier, Make, AI Automation Systems)) - UI/UX Design (Figma) 👉 Let’s start with a FREE 15–30 minute consultation to discuss your project and define the best approach. Contact us today to discuss your project requirements.

I build Flutter apps that ship — not prototypes that stall at 80% done. Over the past 4+ years I've taken 30+ mobile products from a blank repo to the App Store and Play Store, including AI-powered apps, FinTech tools, and real-time platforms used by paying customers today. If you need a developer who can own the full build — architecture, AI integration, backend, deployment — you're in the right profile. What I actually solve for clients: * You have an idea or a stalled project and need someone who can architect it correctly the first time, not patch it later * You want AI features (OpenAI, Gemini, Claude, custom LLM workflows) built into a real product, not a demo * You need Firebase set up properly — Auth, Firestore, Cloud Functions, FCM — so it scales past your first 1,000 users * You want both Flutter and native iOS (SwiftUI) capability under one contractor instead of coordinating two teams Recent work includes: * AI-powered health and fitness apps with OpenAI-driven personalization * Real-time chat and social apps built on Firebase + Socket io * FinTech apps with secure payment gateway integration * NFC-enabled apps for access control and card reading/writing * Alarm and background-service apps requiring native platform depth beyond standard Flutter plugins How I work: * Clean Architecture, testable code, and documentation — so your next developer (or I, six months later) isn't guessing * Direct, frequent communication — no disappearing between milestones * I scope realistically upfront; I don't pad timelines to inflate hours, and I don't lowball to win the job then stall Tech stack: Flutter, Dart, FlutterFlow, SwiftUI, Firebase (Auth, Firestore, Cloud Functions, FCM), REST APIs, OpenAI/Gemini/Claude API integration, Provider, Riverpod, Bloc, GetX, Socket io, Google Maps, NFC, payment gateways. If your project needs someone who can go from Figma file to App Store approval without handing off pieces to three other freelancers. Send me a message with what you're building and I'll tell you honestly whether I'm the right fit.

With 3+ years of hands-on experience, I specialize in taking embedded products from prototype to mass production. I've completed 10+ real-world projects and successfully shipped consumer products that are now in end-users' hands. What I Do Best I build production-grade firmware — not hobby projects. My work spans the full embedded stack: hardware bring-up, device drivers, firmware, bootloaders, OTA systems, and companion mobile/PC apps. Core Expertise - MCU Platforms: STM32 (F0/F1/F4/L0/L4), ESP32/ESP32-S3/ESP32-P4/ESP32-C3, nRF52480/NRF52832, ARM Cortex-M & RISC-V, ... - RTOS & Bare-Metal: FreeRTOS (advanced task sync — queues, semaphores, event groups, task notifications), bare-metal programming, custom bootloader development, ... - Peripherals: I2C, SPI, I2S, UART, PWM, ADC/DAC, RMT, Modbus RTU, USB HID, ... - Connectivity: Wi-Fi, BLE, LoRa, NFC, GSM/GPRS, NB-IoT, 4G, ... - IoT & Cloud: MQTT, HTTP/HTTPS, WebSocket, TCP/UDP | Azure IoT, AWS, Firebase, ... - Security: Secure Boot, encrypted NVS storage, FIDO2 passwordless authentication - Languages: C/C++ (primary), Python, Dart/Flutter (mobile & desktop apps), Java - Sensors: Accelerometer, IMU, Gyroscope, Time-of-Flight (ToF), Fingerprint, Ambient Light, Temperature, Humidity, Water Quality, Gas, Heart Rate & SpO₂, ... - Peripherals: Camera, Microphone, Speaker, Buzzer, ... - Displays: TFT, OLED, LCD, HMI, ,.. - Build & Debug: ESP-IDF, Makefiles, CMake, linker scripts, GCC toolchain, GDB/JTAG — fully IDE-independent - Other: Embedded Linux (Raspberry Pi, Orange Pi), Edge AI on MCUs, VoIP, WireGuard VPN, OTA update systems, PCB design (EasyEDA) What Sets Me Apart I deliver production-ready firmware, not proof-of-concepts. Clean architecture, proper error handling, memory optimization, and power management. I work at the toolchain level — Makefiles, linker scripts, GCC, GDB — not dependent on any IDE. I collaborate effectively with backend teams, including building systems using MCP (Model Context Protocol). I've shipped real consumer electronics — I understand what it takes to go from "it works on my bench" to "it works in 10,000 units." If you're a startup building a hardware product and need someone who can take it from prototype to production, let's talk.

Hi, I'm David. I help turn complex electronic concepts into dependable, production-ready products. With over 5 years of practical experience, I support clients through the full development cycle, from initial design to functional prototypes and manufacturing handoff. My focus is on building efficient, scalable, and cost-conscious hardware systems that perform reliably in real-world conditions. 1. What I Deliver: Embedded Systems & Hardware Development - PCB Design & Hardware Engineering: Circuit design, multi-layer PCB layout, component selection, impedance tuning, compact design, and cost optimization. Emphasis on IPC standards, signal integrity, EMI/EMC mitigation, and thermal considerations. - High-Speed & Complex Systems: Hands-on work with DDR, HDMI, MIPI (CSI/DSI), PCIe Gen1/2, along with SoC and FPGA-based prototyping. - Embedded Platforms: STM32N6, STM32H7/STM32H5, STM32F7/STM32F1/F3/F4, ESP32/ESP8266, Nordic nRF52 series, ARM Cortex-A systems, Raspberry Pi (CM4/CM5), Zynq-7000. - Power & Mixed-Signal Design: Switching regulators (Buck, Boost, Flyback), LDOs, battery systems, motor control (BLDC, stepper, servo, DC), and analog/digital integration, PoE, LLC. - Manufacturing Readiness: BOM preparation, Gerber generation, and design adjustments to streamline production and reduce costs. - Tools: Altium Designer, KiCad, LTspice, Proteus, MATLAB/Simulink . 2. Firmware & Software Development - Programming: C, C++, Embedded C, Python (for automation and validation). - System Development: Linux-based platforms, MCU firmware, RTOS (FreeRTOS), power optimization, bootloaders, OTA updates, and debugging. - Connectivity & IoT: WiFi, BLE, LoRa, Zigbee, GSM/LTE/NB-IoT/5G, GPS, RFID, NFC. - Communication Interfaces: UART, I2C, SPI, I2S, RS232, RS485, CAN, Modbus RTU/TCP, USB, Ethernet. - User Interface: LVGL-driven GUIs, TFT/OLED displays, and touch interfaces. 3. Development Process & Collaboration - Product Lifecycle Support: Concept → prototyping → validation → production handover. - Workflow & Management: Organized development using Git, Jira, and structured documentation with clear milestones. - Global Collaboration: Experience working across US, EU, and Asia time zones with consistent communication. - Troubleshooting: Strong capability in diagnosing and resolving both hardware and firmware issues. 4. Why Choose Me? - Unified Skillset: Combined hardware and firmware capabilities help minimize back-and-forth and speed up delivery. - Practical Engineering Approach: Designs are built with real-world constraints in mind — not just theory. - Efficiency-Oriented: Focus on reducing unnecessary costs while maintaining performance and reliability. - Clear & Responsive Communication: Regular updates, well-documented progress, and quick feedback. Looking to bring your idea into a functional, well-engineered product? Feel free to reach out. I’d be glad to discuss your project !!!