Sophie Alpert
Engineering at Clay
San Francisco, California, United States
Summary
🤩
RockstarSophie Alpert is a seasoned engineering leader with 17 years of experience building developer-facing products and scalable B2B SaaS. Best known for being React’s first production user outside Facebook and later managing the React core team, she helped turn React from a niche experiment into an industry standard used by millions. She’s held senior technical and exec roles—Principal Engineer at Notion focused on performance and product mental models, and VP of Engineering at Humu—bridging hands-on development with team and product strategy. Sophie remains an active open-source contributor across major projects like Jest, Relay, React Native, Babel, and DevTools, with deep expertise in front-end performance, tooling, and testing. Now leading engineering at Clay, she’s applying that product and platform experience to help sales teams sell better. Colleagues describe her as a pragmatic technologist who blends curiosity (and a fondness for dumplings) with the ability to ship large-scale, developer-focused systems.
17 years of coding experience
12 years of employment as a software developer
Stackoverflow
141,375reputation
12.7mreached
442answers
48questions
webkit
top-5%
substring
top-5%
canvas
top-5%
jsx
top-1%
dom
top-5%
twitter-bootstrap
top-5%
Github Skills (103)
datetime10
composition10
flow-control10
python10
testing10
timing10
ruby10
relayer10
bundler10
lowercase10
jtest10
backend10
epoch10
jsx10
optimization10
Programming languages (28)
Github contributions (5)
Khan/khan-exercises
May 2011 - Mar 2015
A (deprecated) framework for building exercises to work with Khan Academy.
Role in this project:
Front-end Developer
Front-end DeveloperContributions:1116 commits, 1 PR, 1 push in 3 years 10 months
Contributions summary:Sophie primarily contributed to the project by modifying JavaScript and HTML files within the `exercises` directory, indicating a focus on user interface elements. They implemented both improvements and adjustments to user interface elements and logic, as evidenced by their changes to the existing HTML/JavaScript files, suggesting a role focused on front-end development. These changes include adding/removing display for math elements, showing and hiding elements, and improving label formatting and placement.
khan-academy
reactjs/react-art
Jan 2014 - Feb 2017
React Bridge to the ART Drawing Library
Role in this project:Front-end Developer
Front-end DeveloperContributions:34 commits, 14 PRs, 17 pushes in 3 years 2 months
Contributions summary:Sophie focused on developing and maintaining React components for the `react-art` library. Their contributions include refactoring code to remove deprecated features, adding examples with webpack for better integration, and fixing warnings in the example code. They also added tests and made adjustments to ensure proper rendering of components, demonstrating a focus on improving the library's functionality and user experience. Furthermore, the user refactored and updated various core components and utilities for efficiency.
reactartbridgedrawing-libraryreactjs
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