Hire the Best Wearables Specialists
in the United States

Embedded systems engineer with hands-on experience across the full product stack — from hardware design and firmware to wireless connectivity and companion apps. I've built and shipped real products along with a variety of prototypes and proofs. **Core Skills:** • Microcontroller firmware (ARM Cortex-M, Nordic nRF series, STM32, ESP32) • Wireless stacks — Wi-Fi, BLE, sub-GHz • Network protocols - MQTT, CoAP, REST, HTTP • PCB design, schematic capture, and hardware bring-up • Mobile & wearable companion apps — iOS, watchOS, Garmin Connect IQ • IoT system integration — cloud connectivity, OTA Firmware, device management • Embedded Linux — Raspberry Pi, single-board compute, display pipelines I work best with startups and product teams who need an engineer that can own a problem end-to-end — from silicon to the app that talks to it.

I am a Senior Embedded Systems Engineer with strong experience in firmware development, PCB design, IoT systems, embedded Linux, robotics, industrial automation, and edge AI. I help clients turn ideas into reliable products by handling the full development process from architecture and component selection to schematic design, PCB layout, firmware, testing, debugging, and production ready documentation. My core expertise includes: - Embedded Firmware: C/C++, STM32, ESP32, nRF52, RP2040, FreeRTOS, Zephyr, bare metal firmware - PCB & Hardware Design: KiCad, Altium, schematic design, PCB layout, BOM, Gerbers, DFM, debugging - Embedded Linux: Yocto, Buildroot, device tree, Linux drivers, bootloaders, system integration - IoT & Wireless: BLE, Wi-Fi, LoRa, Zigbee, MQTT, TCP/IP, OTA updates - Industrial & Automotive: CAN, CAN-FD, RS-485, Modbus, J1939, UDS, PLC/SCADA integration - Robotics & Control: motor control, BLDC/FOC, sensor fusion, real time control, ROS 2 - Edge AI: TinyML, TensorFlow Lite Micro, Edge Impulse, computer vision, sensor based AI - Desktop Tools: Qt/C++, Python automation, serial/CAN tools, test software, firmware update utilities - FPGA Support: Verilog/VHDL basics, FPGA integration, high speed data acquisition support I can support projects such as: - Custom IoT devices - Sensor based embedded products - Wearable electronics - Industrial controllers - Robotics systems - Automotive CAN devices - BLE/Wi-Fi connected products - Embedded Linux gateways - PCB redesign and hardware debugging - Firmware rescue and prototype bringup I focus on building systems that are reliable, testable, manufacturable, and easy to maintain. Whether you need a prototype, firmware fix, PCB redesign, or complete embedded product development, I can help move your project from concept to working hardware. Thank you for visiting my profile. If you're looking for an experienced Embedded AI & IoT Engineer who can help turn ideas into reliable products, I'd be happy to discuss your project. I look forward to working with you.

Alex is the founder of Mass Product Development, a mechanical engineering and product development consultancy focused on helping startups bring hardware products to market efficiently and reliably. He holds a B.S. in Mechanical Engineering from MIT and spent several years at RKS Design in Los Angeles, where he worked on the design and prototyping of consumer and electromechanical products. Alex specializes in taking products from early concept through functional prototypes and into manufacturing readiness, with deep experience in consumer electronics and complex mechanical systems. Alex has thousands of hours of hands-on experience in SolidWorks and Siemens NX, as well as embedded development using Arduino, Raspberry Pi (Python), and Java. His work spans a range of regulated and consumer markets, including medical and dental devices, consumer electronics, children’s products, and fitness equipment, with multiple products successfully launched to market. He works best with teams that value speed, technical rigor, and clear communication. Alex partners with funded startups that need to de-risk designs, control costs, and move quickly toward manufacturing. Whether you need a works-like/looks-like prototype, production-ready CAD, or support getting a product over the finish line, Mass Product Development provides the engineering horsepower to get it done.

I specialize in building iOS apps for health and fitness wearables, delivering seamless BLE integration, real-time data accuracy, and user-focused solutions. With over 12 years of iOS development experience, I help companies create apps that sync effortlessly with devices, boost user retention, and stand out in the market. My proven track record includes: - Prima-Temp: Fixed BLE and data sync issues that had halted a critical clinical study of in-vivo temperature sensor. Achieved successful study with an end result of 97.7% data collection rate. - Rise Science: Built background collection of HealthKit and CoreMotion data, integrating it with an AI API for personalized sleep insights. Fixed reliability issues with the Apple Watch app and iOS widget, ensuring consistent, real-time data flow. - UNICEF KidPower: Rebuilt the BLE stack for a wearable app, enabling real-time activity tracking for kids. Provided technical leadership, contributing to its feature in TIME’s 25 Best Inventions of 2016. From startups to established brands, I bring expertise in HealthKit, Core Bluetooth, and SwiftUI to solve your toughest challenges. Let’s create your next health or fitness app—message me today! # Client Testimonials "Justin builds for scale… we’ve reused his code into new experiences, saving us time and money. His specialty in the wearable market and iOS was the perfect solution to help us meet our challenges." – Ryan Modjeski, UNICEF USA. "Justin demonstrated reliability and definitely shouldered responsibility for the project… It helped me sleep well at night knowing Justin was on it." – Troy Hickerson, Calorie Cloud

AI can move a project forward fast. It can also create architecture nobody trusts, firmware that almost works, security holes no one noticed, ML models that don’t survive real data, and prototypes that fail the moment they touch real hardware. That is where I create the most value. I help founders, inventors, and technical teams use AI aggressively without letting AI-generated mistakes turn into expensive engineering debt. If you are already using ChatGPT, Claude, Cursor, Codex, Replit, Lovable, or other AI tools, but your project is getting stuck because the output is brittle, insecure, poorly specified, hard to validate, or disconnected from real-world constraints, I can help. Think of me as an AI engineering whisperer: someone who understands both the power of AI and the engineering realities that AI often misses. My strongest fit is not commodity implementation. If your project is fully specified and just needs code written, there are many lower-cost options on Upwork. My value is highest when the system is ambiguous, partially built, AI-generated, technically risky, or crossing the boundary between software, hardware, firmware, data, ML, and operations. I help answer questions like: ▸ Is this AI-generated architecture actually safe to build on? ▸ Will this prototype survive real users, real hardware, real timing, and real edge cases? ▸ Are there hidden security, reliability, integration, or model-validation risks? ▸ What should be rebuilt, what should be kept, and what should be tested first? ▸ How do we turn a promising AI-assisted prototype into a real engineering system? MY WORK TYPICALLY FALLS INTO FOUR AREAS: AI ENGINEERING RESCUE ▸ Review AI-generated code, architecture, workflows, and product plans ▸ Identify brittle assumptions, missing tests, security gaps, and failure modes ▸ Turn prototype chaos into a coherent technical path REAL-WORLD SYSTEM ARCHITECTURE ▸ Design systems that work beyond the demo ▸ Bridge AI, software, hardware, firmware, sensors, wireless links, and operations ▸ Translate unclear product ideas into buildable technical specifications APPLIED ML & DECISION SYSTEMS ▸ Build and validate machine-learning models for noisy, real-world decision environments ▸ Work with time-series data, feature engineering, model evaluation, and out-of-sample testing ▸ Identify leakage, overfitting, regime-change problems, and weak validation methods ▸ Develop ML systems where bad assumptions create real financial or operational consequences EMBEDDED, IOT & HARDWARE-AWARE DEVELOPMENT ▸ Firmware, PCB, sensor, wireless, and real-time system review ▸ STM32, ESP32, Raspberry Pi, BLE, cellular, IoT, industrial, and prototype systems ▸ Debug issues where software assumptions collide with hardware reality I have taken numerous products from concept to production, including embedded systems, IoT devices, industrial controls, data systems, automation tools, and AI-enabled workflows. I also build applied ML models for noisy, high-stakes decision environments, including financial market models that I use in my own trading. That work demands strict leakage control, disciplined feature engineering, out-of-sample validation, model-failure analysis, and constant attention to whether a signal is real or just noise. My background includes MSEE-level engineering training, decades of hands-on product development, and extensive practical use of LLMs, agentic AI workflows, and applied machine learning. Most AI consultants do not understand hardware. Most hardware engineers underuse AI. Most ML prototypes are not tested hard enough against real-world failure modes. I bridge those gaps. Best fit for: ▸ Founders building AI-assisted products ▸ Teams with prototypes that work in demos but not in the real world ▸ Companies using AI-generated code and needing review, hardening, or architecture cleanup ▸ Teams building ML, forecasting, automation, or decision-support systems ▸ Embedded, IoT, robotics, sensor, wireless, or firmware projects where AI alone is not enough ▸ Inventors who need a senior technical reality check before spending serious money The value I bring is practical technical judgment. I help you move faster without fooling yourself. A short review can often prevent weeks or months of wrong-direction development. Relevant technical areas: Embedded systems • AI/ML systems • LLM workflows • Agentic AI • System architecture • Applied machine learning • Time-series modeling • Forecasting • IoT • Firmware • PCB design • STM32 • ESP32 • Raspberry Pi • BLE • Cellular IoT • Real-time systems • Sensors • Wireless systems • Product development • Prototyping • Manufacturing readiness • Security review • Automation • Data pipelines • Python • C/C++

Solutions oriented Engineer highly regarded with more than 7 years of progressive experience developing, implementing and supporting product development and research. Experienced Electrical, Biomedical Engineer, Product Developer and Systems Integrator, specializing in prototype development, quality control, product manufacturing and analysis.