Web Crawler This is my current project. I'm endeavoring to crawl 1 billion web pages for a couple hundred dollars. It is ~80% done.

Build Your Own Regex Engine This is a simple Regular Expression engine and corresponding tests. The associated blog post went viral a while back.

React Column Layout | npm package A column based layout system (think Pinterest style) that works responsively without special configuration.

Other Major Open Source Contributions

Sequelize The popular Nodejs ORM.

Gatsby The very same static site generating framework used to build this site