Signal is not demand.
A lesson from building products before proving somebody wanted them.
TOBY SUMERFIELD
Building better systems.
I lead, build, test and learn across sport, systems and AI. This is a record of the experiments, decisions and ideas that survive contact with reality.
FIELD NOTES
Things learned by doing.
Why I killed a running-shoe company I wanted to build.
N=1 began with a problem I genuinely wanted solved. Evidence eventually changed the decision.
Building software got cheap. Finding someone who wants it didn't.
AI changed the cost of making. It did not remove the need for demand.
WORK
Projects, experiments and real-world systems.
My work sits where sport leadership, technology and operations meet. Alongside leading sport in international education, I build and test tools around school sport, professional learning, procurement and decision-making. Some work. Some don't. Both are useful.
Sport systemsAI × real workBuilder's journalChina × execution
IDEAS I USE
Operating principles, not slogans.
Demand Before Supply↗
Minimum Necessary Orchestration↗
Reality Before Representation↗
Public Evidence Compounding↗
READING
Books and writers that changed how I think.
A recurring question runs through much of what I read: how do you use a finite life well, maintain agency over your time, and do meaningful work without blindly accepting the default path?
The 4-Hour WorkweekFour Thousand WeeksThe Obstacle Is the WayMeditationsTo Shake the Sleeping SelfThe OverstoryAlain de BottonThe Almanack of Naval Ravikant
ABOUT
Practitioner first.
I'm Toby Sumerfield, a sport leader and builder based in Shanghai. I've spent nearly two decades living and working in China. I'm interested in what happens when practical leadership, systems thinking and increasingly capable AI meet real work.
This site is not a highlight reel. It is a public record of what I'm building, what I'm learning, what failed, and what changed my mind.