Muhammad J.

Need an Android developer who understands fintech, healthcare, POS terminals, or EV-charging hardware? I build production-grade apps that handle secure payments, card-present transactions, and real-time hardware integrations clients can trust. Most mobile developers haven't touched EMV/NFC payment flows, ISO 8583 messaging, PAX terminals, or OCPP 2.0 EV-charging protocols. I have shipped 7+ Android and hardware-integration projects for an ABB EV-charging terminal ecosystem used across 50+ countries, working directly with payment processors, acquirers, and banks. --------------------------------------------------------------- I can help you with: ✅ Native Android development using Kotlin, Java, Jetpack Compose, MVVM and Clean Architecture ✅ Cross-platform builds with Flutter and Kotlin Multiplatform (KMM) ✅ Fintech and payments: digital wallets, payment SDKs, EMV/NFC, MagStripe, ISO 8583 messaging ✅ POS terminal integration: PAX, Verifone, Ingenico, Adyen and custom unattended hardware ✅ IoT and hardware: MQTT, TCP/IP, OCPP 2.0, MDB/VMC, GPIO, Azure IoT Hub ✅ Security and compliance: OAuth 2.0, JWT, TLS 1.3, PCI DSS, biometrics, KYC ✅ Backend integration: REST APIs, WebSockets, Firebase, offline sync ✅ CI/CD and release management across Google Play, App Store and PAX Store ✅ TESTING & QUALITY – JUnit, Espresso, Mockito, Robolectric, Firebase Test Lab, Detox ------------------------------------------------------------------------------------------------ 📱 INDUSTRY EXPERIENCE ✔ Fintech, digital wallets, KYC and insurance applications ✔ Android POS and card-present payment systems ✔ EV-charging terminals and OCPP 2.0 integrations ✔ Unattended payments and vending-machine integrations ✔ MDB/VMC cashless vending integrations ✔ IoT, SBC and connected-controller applications ✔ U.S. healthcare applications ✔ E-learning and healthcare education applications ✔ Fitness, location and sensor-based applications ✔ Multimedia and video-player applications SELECTED HARDWARE AND PROTOCOLS ✔ PAX IM30, A920 Pro and A35, Sunmi, Verifone payment terminals ✔ Engicam SBCs using Intel and Rockchip processors ✔ MDB/VMC Levels 1–2 and selected Level 3 functionality ✔ Custom POS, SBC and controller hardware ✔ EV-charging and vending-machine controllers ✔ MDB/VMC integrations for vending machines ✔ MQTT, TCP/IP, OCPP 2.0, Modbus and GPIO ✔ RFID readers, NFC and MagStripe devices --------------------------------------------------------------------- 🔥 WHY WORK WITH ME? 🔹 Contributions to 7+ EV-terminal and hardware-integration projects 🔹 5+ years of hands-on Android and mobile engineering experience 🔹 Production experience across fintech, POS, EV charging, IoT and healthcare 🔹 Strong Kotlin, Java, Jetpack Compose and Flutter capabilities 🔹 Clear estimates, milestone updates and early communication about risks 🔹 Regular updates & transparent communication 🔹 Ongoing maintenance and post-launch improvements 📩 Have a fintech, POS, healthcare or hardware-integration project in mind? Send me a message with your requirements and I will reply with a clear plan and timeline within a day.