Esther Chang

Hi, nice to meet you!

I’m Esther, a third-year student in Systems Design Engineering at the University of Waterloo.

Here is my portfolio for your viewing. I’m currently looking for Fall 2026 internships!
If we seem like a good match, feel free to leave a message in the Contact section.

Feel free to click on the buttons with mini portfolios attached to see some of my work!

Internships

Reliability Engineering Intern

Metrolinx | Jan 2026 – Apr 2026

  • Supported Reliability Engineering team in their RCAs as they investigate vehicle malfunctions
  • Developed SOPs for newly implemented processes, improving consistency and efficiency for floor technicians
  • Led the GO Bus surveillance footage distribution system for coordinating secure delivery of data to managers and law enforcement, ensuring timely response and compliance.

Medical Device Technical Intern

Stryker | Sep 2024 – May 2025

  • Inspected and repaired hundreds of medical devices across instruments and consoles (e.g., surgical handpieces, PneumoClear, Core 2, SmartPump), ensuring operational reliability
  • Conducted quality assurance testing on repaired devices to verify compliance with safety and regulatory standards prior to shipment

Mechanical Engineering Intern

UW Baja SAE | Jan 2024 – Apr 2024

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  • Designed and validated the 2025 vehicle suspension systems and engine mount using SolidWorks, FEA, MATLAB, and rapid prototyping (3D printing)
  • Produced detailed engineering drawings and fabricated components using CNC machining (mill, lathe, bandsaw) and soldering
  • Led team operations and external outreach, achieving a 78% increase in partnerships
  • Competed in national Baja SAE competitions against North American teams

Projects

Ontect: Edge AI Security System

Apr 2026

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  • Created an autonomous Edge AI security system using ESP32-S3 to perform real-time human detection
  • Optimized energy efficiency via Deep Sleep and PIR hardware interrupts, aiming to extend battery life from 15 hours -> 3 months

Heart Rate Sensor + Love Detector

Nov 2025 – Dec 2025

  • Designed a physical photoplethysmography (PPG) heart rate sensor prototype, integrating IR diodes and ICs to accurately capture and output real-time physiological data.
  • Extended to a dynamic frequency-detection hardware system by cascading analog filters, peak detectors, and comparators to trigger automated outputs based on specific heart rate thresholds.

Cochlear Implant Signal Processor

Oct 2025 – Dec 2025

  • A multi-band audio signal processing system in MATLAB to simulate cochlear implant functionality and reconstruct complex acoustic outputs.
  • Designed a verification framework, utilizing quantitative acoustic metrics (VISQOL, STOI, SNR) to validate output clarity and speech intelligibility.
  • Developed automated diagnostic tools for continuous signal preprocessing, noise analysis, and waveform visualization.