← All the people Dennis builds with
Chris Rummel
Chris Rummel was Dennis’s close friend and co-founder. They were engineers at Yahoo, and their friendship was built on a rhythm of shared activity. Every Tuesday and Thursday, they played ultimate frisbee. They ran marathons together, a habit that led to the photo in the library: the two of them after the 2001 Portland Marathon, still wearing their finisher shirts. Their bond extended beyond the track and the field into the professional sphere, where they built a software company together.
Their venture focused on training optimization, using run data, heart rate, and nutrition to adjust training plans automatically. This approach predated the current wave of AI tools, and they grounded their methods in physiology journals rather than magazines. The software gained traction with professional athletes, and Hal Higdon and the Chicago Marathon community agreed to use it. Chris also worked as a flight instructor at Embry-Riddle. When he was getting married and needed money, Dennis withdrew $20,000 from Bank of America that afternoon. Chris was too proud to accept it as a gift and insisted on selling Dennis his Volkswagen GTI instead. Dennis did not want the car, and Chris subsequently rode his motorcycle to work.
Chris died after a motorcycle accident in Mountain View. Dennis has said he never forgave himself for not fighting harder, noting that a voice had warned him weeks before. When Dennis tried to honor Chris by releasing the software, the code was locked behind Chris’s credentials. Undocumented work died with the person. That lesson—Learn, Do, Teach—drove Dennis to build in public. He now shares workflows openly, ensuring that if a process exists, it does not vanish with a single session or individual. When Dennis watches Trenton Sandler build in public with Grant, he sees what he and Chris had, done smarter.
The photo gallery includes images of Dennis and Chris between gates, an older print of them being idiots in a booth, and Chris in a Dallas Star-Telegram shirt. There is also a photo of Chris on a course, his face down on the swing. The Tuesday and Thursday frisbee shots are not in this set. Photo gallery coming - Dennis will narrate.
Photos with Chris Rummel
This page is part of how Dennis Yu honors the people he builds with — real pages that link real work, so the people he believes in rank on their own names. Meet the rest →