WL

William Li — software developer

I build web apps, AI tools, AI workflows, ML systems

Sacramento, CA
Sacramento, CA 5 projects · 2026 Software developer & CS student
  • Python
  • TypeScript
  • React
  • Node.js
  • C++
  • Java
  • three.js
  • LightGBM
  • uv
  • Git
  • Tailscale
  • Cloudflare Pages

A little about me

I like building software that feels fast and stays honest. Small first loads, real numbers, and the details you only notice when they are missing. Less talk, more shipping.

Featured projects

Work that shipped, with the numbers

Four featured projects from 2026 — live apps, private research and open-source tools. The full list, including works in progress, is on the projects page.

All projects
paurk — product screenshot

Live 2026 Web app · 3D

paurk

Quiet-spot discovery for right now

A fully client-side web app that ranks 1,229 public places across 89 cities in 60 countries for the current moment — sun, weather, chosen vibe and walking distance — on a custom three.js globe. No backend, no map tiles, no API keys.

  • 1,229 places ranked
  • 89 cities · 60 countries
  • 170 KB first load, gzipped
  • React
  • TypeScript
  • three.js
  • Vite
  • Vitest
  • Cloudflare Pages
BTC paper-trading system — product screenshot

Private 2026 Trading systems · ML

BTC paper-trading system

An automated signal-to-execution pipeline that models the boring parts

An end-to-end paper-trading engine: Binance data ingestion, market-structure features, a LightGBM signal model with rolling retraining, and a backtester that models exchange fees, position sizing and risk — running across a Mac and a Windows box over Tailscale.

  • 0.567 rolling AUC
  • 90 days of OHLCV
  • Python
  • Node.js
  • LightGBM
  • pandas
  • Tailscale
Learn Pickleball — product screenshot

Live 2026 Desktop · C++

Learn Pickleball

A desktop rules trainer that keeps asking until you know it

A C++17 desktop application that teaches pickleball rules through eight lessons with animated court diagrams, backed by an adaptive quiz engine that resurfaces missed questions until you demonstrate mastery.

  • 8 animated lessons
  • Adaptive quiz engine
  • RAII resource model
  • C++17
  • SFML 3
  • STL

Skills

What I work with

  • TypeScript
  • React
  • three.js
  • Node.js
  • Python
  • pandas & NumPy
  • LightGBM
  • C++
  • Java
  • Cloudflare
  • Vite
  • Playwright
  • GitHub
  • Linux
  • Tailscale
  • uv

Stack

01 Languages

  • Python
  • TypeScript
  • JavaScript
  • C++ (C++17)
  • Java
  • HTML/CSS

02 Libraries & frameworks

  • React
  • Node.js
  • three.js
  • LightGBM
  • pandas
  • NumPy
  • SFML 3
  • STL

03 Tools & platforms

  • Git/GitHub
  • uv
  • Cloudflare Pages & Functions
  • Tailscale
  • Vite
  • Vitest
  • Playwright
  • REST APIs
  • Linux
  • macOS
  • Windows

Certifications

  • Foundations of Data Science Google Aug 2026
  • Supervised Machine Learning: Regression IBM · Coursera Aug 2026

About

Student by day, shipping by night.

I study computer science at American River College in Sacramento, on the transfer track toward the CSU/UC system. Coursework so far covers data structures, discrete structures, object-oriented C++, linear algebra, calculus and electricity & magnetism.

Outside class I build products end-to-end: front-end and 3D on the web, serverless back-ends on Cloudflare, data and ML pipelines in Python, and native tools in C++. Everything on this page is live or open source.

Based in
Sacramento, CA
Studying
Computer Science
School
American River College
Open to
Internships & collabs
  • 5 Projects in 2026
  • 316 Automated tests in one project

Education

American River College

Sacramento, CA

Coursework

  • Data Structures
  • Discrete Structures
  • Object-Oriented Programming in C++
  • Linear Algebra
  • Calculus
  • Physics: Electricity & Magnetism

Off the clock

A few things I care about that are not on a résumé

  • PC hardware & custom water cooling
  • Algorithmic trading
  • Pickleball
  • Car enthusiast

Contact

Let's build something.

Internships, collaborations, or a question about one of the projects — my inbox is open.