Resume

Jef Wagner · Appleton, WI · jefwagner@gmail.com · (405) 364-4073 GitHub: github.com/jefwagner

Summary

Physicist-turned-embedded-engineer who builds systems from the hardware up. 18 years of experience across Rust/C/Python - from bare-metal RTOS to embedded Linux to high-performance computing clusters. Designed the telematics architecture for Pierce Manufacturing's next-generation fire apparatus. Looking for a technical role where I can build things, mentor engineers, and work in an environment that favors spontaneous collaboration over scheduled meetings.

Technical Skills

Languages: Rust, C, C++, Python, Zig, Bash Embedded / Systems: Embedded Linux, RTOS (FreeRTOS), CAN bus, I2C, SPI, MMIO, ARM Cortex-M, ESP32, RP2040 Tools: Git, Jupyter, Docker, CI/CD, HIL testing, oscilloscopes, logic analyzers Domains: Real-time systems, data analysis & visualization, statistical modeling, HPC, audio DSP, control systems

Employment

Senior Principal Engineer, Software — Pierce Manufacturing

Appleton, WI | September 2020 – Present

• Designed the on-vehicle telematics system architecture — an embedded Linux Rust application collecting and transmitting vehicle data over CAN bus.
• Built the RTOS data-point collector running on a HCS12 microprocessor, handling real-time sensor aggregation from multiple CAN buses.
• Led the redesign of the Hardware-in-the-Loop (HIL) testing framework, writing the Python interface and first automated test suite for a new product program.
• Mentored two junior engineers through the full lifecycle of a production-intent embedded project.
• Diagnosed an intermittent wig-wag light timing failure by comparing CAN trace data with Python/Plotly timestamp analysis. Root cause: a timer update in a 10ms RTOS task was skipped when CAN queue processing overran. Moved the timer update to the 1ms priority task.
• Traced a rare CAN message corruption bug (~5% of trucks, monthly incidence) to a race condition in the vendor-supplied CAN driver - a mutex was released between copying the message ID and data. Patched the driver locally, rolled it out to all active telematics customers.

Assistant Professor — Union College (Physics Department)

Schenectady, NY | September 2017 – August 2020

• Taught upper-division physics courses (classical mechanics, E&M, computational physics) and introductory physics for life science majors.
• Designed and built undergraduate research projects on viral shell assembly and polymer simulations using coarse-grained molecular dynamics in C++ and Python.
• Advised 5 undergraduate research students - 4 computational, 1 experimental - all presented at local symposia, 2 at national meetings.
• Produced 20+ scripted explainer videos for two courses during COVID remote transition.

Visiting Assistant Professor — Lawrence University (Physics Department)

Appleton, WI | September 2014 – June 2017

• Taught 10+ distinct courses from introductory physics for non-majors to advanced mechanics for physics majors.
• Introduced computational physics into the curriculum using Jupyter notebooks.
• Designed a soft matter physics course with a focus on simulation-based exploration.

Postdoctoral Scholar — UC Riverside (Physics Department)

Riverside, CA | June 2010 – July 2014

• Developed coarse-grained simulations of RNA packaging and viral capsid assembly on HPC clusters.
• Published 8 peer-reviewed papers in Physical Review Letters, Biophysical Journal, and related journals.
• Developed the C-method for Casimir force calculations on periodic gratings — a technique from optics applied to Casimir physics for the first time.

Notable Projects

Telematics Edge Application

Rust, Embedded Linux, CAN bus, RTOS, MQTT, TLS

Designed and implemented an on-vehicle telematics system from scratch. A Rust application on embedded Linux reads vehicle data from a CAN bus via an RTOS-based data-point collector on a HCS12 microcontroller. Data is encrypted, filtered, and transmitted to the cloud over cellular. Security was the primary design constraint - hardware is field-accessible for service, but application-level access goes through authentication. Concept to production in ~2 years.

CAN Driver Race Condition Debug

CAN bus, driver debugging, PCAN, Python

Occasional corrupted fault messages on ~5% of trucks, roughly monthly. Built a bench setup replaying CAN traces in a loop for a week to reproduce. Root cause: the vendor's CAN driver released a mutex between copying the message ID and the message data - a window measured in microseconds. Patched the driver source locally, rolled out to all active customers.

Hardware-in-the-Loop Test Framework

Python, CAN bus, analog/digital I/O, CI/CD

Helped redesign Pierce's HIL simulator for fire apparatus ECUs. Built a Python abstraction layer that let engineers write test scripts without touching the HIL hardware API directly. Became the standard for new product testing.

C-Method Casimir Calculations

Scattering theory, computational methods, numerical analysis

Developed a new approach for calculating Casimir forces between a gold-coated sphere and a periodic grating - a geometry no existing method could handle. The results matched experimental data from Umar Mohideen's group. Published in Physical Review Letters (Banishev et al. 2013) and Physical Review A (Wagner & Zandi 2014).

Education

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