About

Hi, I'm Levi. I'm a problem-solving addict and I prefer to tackle the so-called impossible.

I've had a long-standing interest in machine learning and neural networks. Right now I'm obsessed with agentic systems and the future of how we build software.

I've spent 16 years building software and leading teams, including 8 years at Microsoft. I've founded a W3C community group, shaped web standards in WHATWG and CSS WG, and architected design systems powering Microsoft's biggest products.

I operate at the intersection of deep technical work and organizational leadership. I can go from writing the code to aligning the orgs. I build cross-team, cross-company coalitions around hard problems and I ship the solutions myself.

I'm at home in TypeScript, Node.js, and React. I build frameworks, design systems, APIs, CLIs, and full-stack systems. I own the toolchain — build systems, CI/CD, infrastructure, databases. I write tests and hold a high bar for quality. Along the way I've shipped production work in Python, Django, Ruby, C#, and others.

Nothing pleases me more than simplicity and productivity.

Cheers!

Projects

A selection of what I've built. Reach out if you'd like to see more.

Rubber Ducky screenshot

Rubber Ducky 2023 - 2026

Why? Convinced LLMs were the new transistors, I set out to build the future of the developer experience from the ground up.

How? An agentic developer tool — local server powers CLI and UI with full system access (fs, browser, APIs). Framework-free build, model-agnostic (Anthropic, OpenAI, Azure, Ollama), pushing the limits of LLM-driven automation.

Impact: Organically adopted by 2,000+ engineers across 40+ Microsoft orgs. Became officially recommended tooling alongside GitHub Copilot and Claude Code.

Technologies: Docker, Node.js, Express, PostgreSQL, Neo4j, sqlite, Anthropic AI SDK / API, Azure, OpenAI, Ollama, React, Cytoscape.js, Webpack, yargs, pkg, and many others.

Open UI screenshot

Open UI 2019 - 2020

Why? I wanted to eliminate the need to build UI frameworks by pushing design system primitives down into the web platform itself.

How? W3C Community Group, cross enterprise. Analyze top UI design systems and frameworks, synthesize their needs into platform specs and ship in browsers. Members from Google, Apple, Salesforce, Mozilla, Microsoft, Shopify, Adobe, and more.

Impact: After I scaffolded the system and process, immediate success with memberships and adoption. Ongoing specifications and browser updates continue. Grew to lead efforts in WHATWG and CSS WG.

Technologies: W3C, WHATWG, CSS WG, HTML, CSS, and many others.

Code Docs
Fluent UI React screenshot

Fluent UI React 2018 - 2022

Why? As Microsoft Teams' framework lead, I needed a design system and UI library which could unify Teams and M365 products.

How? Created a cross-org cross-product design to code flow to support legacy, enable the future, and achieve >30% performance increase in the process.

Impact: Powers Microsoft Teams, OneDrive, SharePoint, Word, Excel, PowerPoint, and other products. 20k GitHub stars and used in the open source as well.

Technologies: React, TypeScript, Storybook, CSS-in-JS (Griffel), Accessibility, Focus Management, Design Tokens, and many others.

Code Docs
Semantic UI React screenshot

Semantic UI React 2015 - 2017

Why? My team needed a React port of Semantic UI. The existing ports weren't up to standard, so I built one.

How? Rewrote Semantic UI's components in React from scratch. Originally named Stardust, it was chosen by the Semantic Org to become the official React port.

Impact: Adopted by Amazon Publishing, Netflix's Edge Developer Experience team, Netflix's FlameScope, and Microsoft Teams prototyping.

Technologies: React, Babel, Webpack, Gulp, Karma, Semantic UI, and many others.

Code Demo Docs
Anny screenshot

Anny 2015 - 2016

Why? I wanted to understand artificial neural networks from first principles.

How? An artificial neural network lib for Node.js and the browser. A network state and training visualizer.

Technologies: Angular, Babel, Gulp, Webpack, vis.js, Mocha, and many others.

Code Demo Docs

Open Source

I contribute upstream. See more in my forks on GitHub.

karma-runner/karma

Test runner for JavaScript.
Merged some features.

Semantic-Org

UI component framework.
I'm an admin.

less/less.js

CSS preprocessor.
Merged some features.

mikeal/watch

File watcher utility for Node.js.
I'm a contributor.

shelljs/shx

Unix shell commands for Node.js.
Initial setup and tests.

bgrins/TinyColor

Color manipulation and conversion library.
Merged many features and helped plan the v1 API.

Contact

I'd love to chat. I'm looking for hard problems, high stakes, and people who ship.

Let's build something that matters.

me@levithomason.com LinkedIn GitHub