Wiki: Index

James Han
November 2024
Contact
Email jameshan.cs@gmail.com
GitHub @lxyhan
LinkedIn /in/jameshan27
Instagram @jameshan05
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First created Nov 21, 2025
Last edited Jun 7, 2026

Hi, I’m James. I’m a 20-year-old student from Toronto. This wiki contains my research and engineering notes, plus writing across topics like programming languages, geography, and training for the National team in the Triathlon.

Currently

  • Incoming at Wealthsimple’s data science and machine learning team.
  • Retrieval and search infrastructure behind LLMs, Shopify, Sidekick + CX R&D.
  • ML and networking research, Firefox privacy. Designed the methodology and the model: per-request bandwidth-cost estimation for blocked tracker requests, on-device ONNX inference, ~210M users. Coauthored the paper (under review); built the enhanced tracking protection metrics surface it feeds. Gecko security patches on the trust boundary.
  • Built open-source software used by 30k+ students.

About me

  • I enjoy ultras and triathlons! Training for the Canadian team for 2027 worlds, and racing a few 100km/80km trail races this year.
  • I competed in debate internationally and coached students for four years.
  • I’m a geography nerd. I have a collection of maps I find interesting (please ask me!!), and geek out on Geoguessr.
  • I have a very, very cute cat.

Built with Gleam, Rust, and Astro.

Index

  • Systems and ML at Firefox. Six months on the Firefox Privacy team: a multi-process aggregation system in Gecko's C++ engine, security patches on the trust boundary, machine learning research, and a new-tab privacy surface shipped to 210M users.
  • Search Infrastructure and Software Engineering at Shopify. Working notes from my engineering internship on Shopify's Sidekick and CX R&D team in Toronto, building the search infrastructure and software behind the help tooling around Sidekick. Mostly search and systems, with some applied LLM work. Written as I learn it.
  • Machine Learning
  • Open Source Contributions. Engineering on MarkUs and PythonTA, two open-source tools maintained at the University of Toronto and used across the CS department.
  • Linear Algebra
  • Triathlon
  • Writing. Personal notes that I'm okay sharing publicly.