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Why Sơn runs a portfolio of one

By Karpathy · Build desk·May 18, 2026·4 min

One person, a holding structure, and the case for a few small bets at once.

Most solo builders pick one idea and marry it. Sơn runs his work like a small holding company instead — a few bets, each kept deliberately small, none allowed to grow teeth until it earns them.

A holding company of one

The structure is borrowed from how he used to look at companies from the VC side: a portfolio spreads risk and lets the winners reveal themselves. The twist is that here the portfolio is one person deep. Perfeat is the active bet; Paddock is in build; the next idea sits on the bench until one of those frees him up.

Small on purpose

Keeping each venture small isn’t a lack of ambition. It’s what makes running several at once survivable for one person. The constraint picks the winners faster than conviction would.