EMBEDDED FIRMWARE ENGINEER

Hi, I'm Dax Rajani

ARM Cortex M production firmware · BLE · NFC · Sub GHz · secure OTA · ship-ready systems

Develop embedded firmware solutions with 1.5+ years of production experience across 4 shipped projects on ARM Cortex M processors. Deliver BLE 5.x, NFC, Sub GHz wireless, FreeRTOS, secure OTA bootloaders, and crash diagnostics. Complete MEng ECE at Concordia University in 2026.

Download Resume

Production Experience At A Glance

Field Proven Metrics

4Production Firmware Projects Shipped
3ARM Cortex-M Architectures (M0+, M4, M33)
450+Deployed Nodes in Production
3Wireless Protocols (BLE 5.x, NFC, Sub GHz RF)

Work Experience

Where I've worked and what I built

Glide Technology Pvt. Ltd.

Ahmedabad, Gujarat, India

Associate Engineer, Embedded FirmwareFull-time
Jul 2023 – Aug 2024
  • Resolved a production memory leak under a manufacturing deadline by delivering a validated golden firmware image before a 450+ unit production run, preventing field failures across the full batch.
  • Reduced embedded device power consumption by 30% by restructuring FreeRTOS task architecture from periodic polling to interrupt driven event handling, extending battery life without reducing real time data throughput.
  • Identified and fixed a rare concurrent timing defect in a real time BLE ranging system by developing a systematic reproduction strategy, reducing an intermittent once per day bug to a reliably reproducible state within 3 days.
  • Built a remote firmware crash diagnostic pipeline that enabled coredump retrieval from deployed embedded devices over a Sub GHz wireless network with automated cloud upload, eliminating the need for physical hardware access during field debugging.
  • Extended a multi target OTA firmware update system to support a BLE fallback delivery path with persistent state across 3 coprocessors and CRC validation, ensuring update integrity when the primary wireless connection was unavailable.
  • Implemented BLE central role connection management and GATT characteristic data parsing on a secondary wearable device to establish real time sensor data transfer from a paired primary device.
  • Performed multi-temperature battery discharge cycle testing at 0°C, room temperature, and 50°C to generate and validate a production fuel gauge golden image.
Embedded CARM Cortex-MFreeRTOSBLESub GHz RFUARTSPIUSBOTA/DFUA/B Firmware UpdateCRCMemfaultJTAGOscilloscopeLogic AnalyzerGit
Software Engineering Intern, Embedded SystemsInternship
Dec 2022 – Jun 2023
  • Diagnosed and resolved a production critical BLE firmware memory exhaustion defect within 2 weeks. Heap allocations in the BLE scan path were causing initial hardware validation units to reset every 5 to 10 seconds. Delivered a stable golden firmware image before the scheduled 450+ unit production run and prevented the defect from reaching the full batch.
  • Prototyped a wireless proximity and ranging system on an ARM Cortex M33 BLE system on chip, implementing RSSI based distance calculation with frame validation logic that filtered malformed sensor packets.
  • Built practical foundation in bare metal C, FreeRTOS, ARM Cortex M, BLE, NFC, Sub GHz wireless, UART, SPI, I2C, JTAG debugging, and production crash diagnostics.
Embedded CARM Cortex-M33BLENFCFreeRTOSYocto LinuxI2CSPIUARTJTAGLogic AnalyzerOscilloscopeGit

Projects

Things I've built

ARM Cortex M BLE development board running Dax BLE firmware connected via mobile scanner

Zephyr BLE Sensor Node

Embedded Firmware Project: Zephyr BLE Peripheral

Engineering BuildEmbedded Firmware

Developed BLE 5 peripheral firmware on an ARM Cortex M BLE controller using Zephyr RTOS. Implemented a custom 128 bit GATT service with temperature, humidity, and configurable sample rate characteristics. Added LE Secure Connections pairing, per characteristic CCCD notification tracking, NVS backed settings persistence, beacon style URL advertising, and automatic readvertising on disconnect via Zephyr work queue. Deployed and tested on development hardware.

CZephyr RTOSBLE 5GATTARM Cortex M BLE ControllerLE Secure ConnectionsNVSEmbedded Security
View Code

Secure A/B OTA Bootloader on ARM Cortex M Controller

Embedded Firmware Project: Zephyr + MCUboot

Engineering BuildEmbedded Firmware

Built a production OTA firmware update system on an ARM Cortex M controller using MCUboot with swap scratch A/B slots, ECDSA P256 image signing, and BLE SMP wireless delivery. Implemented automatic image confirmation and rollback on boot failure, static partition pinning across SDK upgrades, and GitHub Actions CI that builds and verifies signed binaries on every push. Applied prior production experience from multi target firmware update systems used in commercial wearable products.

CMCUbootZephyr RTOSBLE SMPECDSAARM Cortex M ControllerOTAGitHub Actions
View Code

BLE RSSI Distance Classifier

Embedded ML Project: On-Device Inference on Zephyr

Engineering BuildEmbedded ML

Built an on-device ML classifier that buckets a BLE device's distance into near, mid, and far from RSSI alone on an ARM Cortex M BLE controller running Zephyr RTOS, with no extra hardware. Wrote a BLE observer firmware and host pipeline to collect and label 850 samples, trained an INT8 quantized dense network, and implemented a hand-rolled INT8 forward pass in C without TFLite Micro, verified against an independent Python reimplementation. Reached 96.2% held-out accuracy, beating a hand-tuned threshold baseline by 20.7 points, with 61 to 91 µs on-chip inference latency. Backed feature and architecture choices with a sweep and benchmarked head to head against an Edge Impulse AutoML pipeline on the same dataset.

CZephyr RTOSBLETinyMLINT8 QuantizationPythonARM Cortex M BLE ControllerEdge Impulse
View Code

BLE Clock-Skew Fingerprinting

Embedded Security Research: RF Side Channel Analysis

Engineering BuildEmbedded Security

Tested whether crystal oscillator timing drift, a side channel outside the Bluetooth specification's threat model, can defeat BLE MAC address randomization. Built passive Zephyr BLE observer firmware on an ARM Cortex M BLE controller that logs every advertisement with millisecond timestamps, then a Python pipeline that fits each device's clock fingerprint from its advertising interval sequence while accounting for BLE's mandatory random advDelay dither, and matches vanished and appeared MAC pairs by statistical confidence. Validated the method against synthetic ground truth data before running a 1 hour real capture of 133,210 packets across 60 ambient devices, which caught a MAC rotation cleanly and surfaced and fixed three real bugs in the matching pipeline.

CZephyr RTOSBLEPythonSignal AnalysisPrivacy & SecurityARM Cortex M BLE Controller
View Code

Scalable E-Commerce Analytics Pipeline

Distributed Systems Project: Spark + GCP Dataproc

Engineering BuildSystems Analytics

Built a distributed analytics pipeline for a 42M event ecommerce dataset with ETL, sessionization, funnel conversion, attribution, and anomaly detection stages. Executed live cloud benchmarks and scaling experiments, and delivered an interactive dashboard for job execution, logs, VM metrics, and fault tolerance demonstrations.

Apache SparkGCP DataprocPySparkPythonFlaskGoogle Cloud Storage
View Code

Health Symptom Analyzer

Machine Learning Project: Calibrated Ensemble Classifier

Engineering BuildMachine Learning

Built a symptom based multi class disease classification system using a calibrated soft voting ensemble of KNN, Naive Bayes, Decision Tree, Random Forest, SVM, Logistic Regression, and XGBoost. Added a confidence based escalation policy with thresholds tuned on a validation set that flags inconclusive predictions for clinician review, a shared inference layer served through both a Streamlit UI and a FastAPI REST service, calibration reporting with reliability curves, ECE, and Brier score, and automated tests with CI validation.

Pythonscikit-learnXGBoostFastAPIStreamlitPandaspytestGitHub Actions
View Code

Skills

Technologies and tools I work with

Languages

CEmbedded CC++PythonBash

Microcontrollers & SoCs

ARM Cortex-M0+ARM Cortex-M33ARM Cortex M BLE ControllerARM Cortex-M0+ BLE SoCARM Cortex-M33 BLE SoCMicrochip Sub GHz SoCNXP MCUs

RTOS & OS

FreeRTOSZephyr RTOSYocto LinuxEmbedded Linux

Wireless Protocols

BLE 5.x (Central + Peripheral)NFC (ISO 14443)Sub GHz RF (star topology)Beacon URL Advertising

Communication Protocols

UARTSPII2CUSBCRC Validation

Bootloaders & OTA

MCUbootA/B swapECDSA P256 image signingBLE OTAUSB DFUmulti-target OTAdual stage bootloaderimgtoolDFU

Crash Diagnostics

Memfault (coredump, trace events, reboot tracking, metrics heartbeat)

Cryptography & Security

ECDSA-P256ECDHSHA 256NFC password protectionsecure boot

Debug & Tools

JTAGJ-LinkGDBSEGGER RTTOscilloscopeLogic AnalyzernRF Connect SDKwestEclipse CDT

ML & AI

PyTorchscikit-learnXGBoostNumPyPandasMatplotlibStreamlit

Tools & Workflow

GitApache SparkGCP DataprocMATLABAgile

Core Stack

CARM Cortex M BLE ControllerFreeRTOSBLE 5.x (Central + Peripheral)JTAGPyTorchGit

Education

Academic background

Master of Engineering (MEng)

Electrical and Computer Engineering

Concordia University

Montreal, QC, Canada

Sep 2024 – May 2026
Applied Machine LearningComputer Neural NetworksBiological and Medical Image ProcessingEmbedded SystemsDistributed Systems

Bachelor of Technology (BTech)

Computer Engineering

Ganpat University

Gujarat, India

Jul 2019 – Jun 2023

GPA: 8.54 / 10 CGPA

Achievements & Recognition

A few things beyond the IDE

Emerging Star of the Year 2023-24

Jul 2024

Glide Technology Pvt. Ltd.

Awarded for exceptional technical contributions and firmware improvements across multiple client production projects.

Certificate of Excellence: Volunteer of the Year 2023-24

Jul 2024

Glide Technology Pvt. Ltd.

Awarded for organising corporate events and managing digital content for company social media channels.

Director General Award

Jan 2023

Ganpat University

University-level academic and achievement recognition.

Baroda Achiever Award: Best in Sports

Jun 2022

Bank of Baroda / Ganpat University

3x Provincial and District Gold Medals: Powerlifting

2020 – 2023

Competitive Powerlifting

Provincial and district gold medal wins demonstrating sustained high-performance discipline and resilience.

Contact

Open to embedded firmware, AI embedded, and systems engineering roles across Canada.

Let's Talk

Currently available for full-time roles.
Response within 24 hours.

daxrajani@gmail.comlinkedin.com/in/daxrajanigithub.com/daxrajani
Montreal, QC, Canada

Open to relocation anywhere across Canada: in-person, hybrid, or fully remote.