Ruby on Rails Websites

Michael Hartl is a theoretical physicist with a background as a technology entrepreneur. He is the founder of Tau Day and author of The Tau Manifesto, and the creator of the Ruby on Rails Tutorial. He cofounded Learn Enough and is the principal author. He is an alumnus of Harvard, Caltech, and Y Combinator. As a graduate student and postdoc at Caltech, he studied black hole dynamics and was an instructor in theoretical and computational physics, receiving a Lifetime Achievement Award for Excellence in Teaching. At the request of Kip Thorne, he served as Caltech’s editor for an update to The Feynman Lectures on Physics. Since the acquisition of Learn Enough, he has been focusing on reconnecting with his physics roots, beginning with a systematic course of study in mathematics.

I'm a founder, product engineer, and educator based in New York City. I build software that helps people learn, grow, and ship faster. I founded Flatiron School, where I taught 10,000+ students to code and built Learn.co, the LMS that inspired GitHub Codespaces. Along the way, I co-founded Kode With Klossy with Karlie Kloss. Currently, I'm building AI-powered tools and exploring how agents can transform developer workflows. I believe in shipping fast, solving real problems, and using AI to amplify what's possible.

This website serves as my digital garden where I plant ideas, write tutorials, and showcase my projects. Thank you for visiting!