Charles Lo

Software Test Development Engineer @ Coherent

Charles Lo

Embeded software engineer focused on systems, test automation, and products that talk to real hardware.

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Charles Lo in University of Wisconsin–Madison graduation regalia

About

A short introduction

I am a embedded software engineer with a Computer Science and Physics background, now pursuing my M.S. Computer Science at Georgia Institute of Technology (Specializing in Computing Systems). I like writing software that has to be correct on a bench: instrument control, firmware, and the APIs around them.

I have interned at Coherent and Lintes, and I co-founded UJIN Media. I am looking for full-time software engineering roles.

Education

Where I studied

  • Georgia Institute of Technology

    M.S. Computer Science, Computing Systems Specialization

    Aug 2026 – Present

    Atlanta, GA

    Database Systems DesignMachine Learning

  • University of Wisconsin-Madison

    B.S. Computer Science, Physics; Undergraduate Certificate in Entrepreneurship

    Sep 2022 – May 2026

    Madison, WI

    Computer ArchitectureDigital SystemsOperating SystemsSignals and Systems (DSP)AlgorithmsUI/UX

Work Experience

What I have shipped

  1. Coherent Corp.

    June 2026 – Present

    Fremont, CA

    Radio Frequency Engineer Intern - CPO Software Test Automation Development

    • –Developed COBS, a Python/Tkinter application that coordinates two Keysight N7733C optical switches as a unified 32-channel test system.
    • –Integrated PyVISA/SCPI, serial, and vendor-driver interfaces for optical routing, live power monitoring, FlexDCA measurements, and eye-image capture.
    • –Automated 32-channel optical-power and DCA characterization workflows with configurable settling, retry handling, Excel reporting, and PNG exports.
    • –Implemented instrument identity checks, route readback verification, active-path interlocks, error isolation, and mock/dry-run modes for safer bench operation.
    • –Built mocked instrument adapters and a software regression suite covering routing, automation, GUI behavior, measurement workflows, and report generation.
    • –Packaged the application as a standalone Windows executable and documented its architecture, setup, validation procedures, and operational limitations.

  2. ÜJIN Media

    May 2025 – June 2026

    Chicago, IL

    Co-Founder, Product & Engineering

    • –Architected and developed a full-stack web platform using React, FastAPI, and MongoDB to automate personalized portfolio website creation.
    • –Built REST APIs, authentication workflows, image-processing features, and real-time website preview functionality.
    • –Integrated AI-assisted content and layout-generation features into the platform.
    • –Led a four-person cross-functional team, translating product requirements into technical milestones and development plans.
    • –Helped advance the company into StartingBlock Madison’s Level Set startup incubator program.

  3. Lintes Technology Co. Ltd

    May 2024 – Aug 2024

    New Taipei City, Taiwan

    Software Test Development Engineer Intern

    • –Developed C and C# utilities to support low-cost bit error rate testing of high-speed DAC cables.
    • –Modeled transmission-line behavior and evaluated signal integrity performance using QucsStudio.
    • –Set up and configured production-line test equipment for cable validation workflows.
    • –Supported troubleshooting and verification of test setups during production bring-up.

  4. Lintes Technology Co. Ltd

    May 2023 – Aug 2023

    New Taipei City, Taiwan

    Signal Integrity Engineer Intern

    • –Characterized high-speed interconnects using S-parameter measurements, including impedance, insertion loss, return loss, and mode conversion.
    • –Operated a vector network analyzer to evaluate signal integrity across interconnect channels.
    • –Developed Python-based control scripts for microcontroller-driven switching hardware used in test setups.
    • –Assisted with engineering prototype debugging through HFSS simulations and optical power measurements.

Projects

Selected work

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Skills

What I work with

Software

PythonCC#JavaMATLABReactFastAPIMongoDB

Hardware / Test

PyVISASCPIOscilloscopes / DCAVNAOptical power metersBER testingMicrocontrollers

Tools

GitQucsStudioHFSSLinuxWindows

Languages

English (fluent)Mandarin Chinese (fluent)Spanish (intermediate)