Antoni Gmitruk

Warsaw, Poland / SF, Cali

About

I build software. Most of my time right now is spent exploring what to build next.

I also help run the MD Fellowship, a programme for early-career builders in Poland. Each cohort gets mentorship, introductions and a community of other builders.

Until recently I was cofounder and CTO of Golf, a YC company building security for enterprise MCP.

You can reach me on X, LinkedIn or by email, and you can check out my builds at GitHub.

Work

  • Aug 2026 – nowBuilding something new.
  • Feb 2025 – Aug 2026Golf (YC X25). Cofounder & CTO.
  • Mar 2024 – nowCofounder, MD Fellowship.

Writing

I write on Substack — thoughts from the battlegrounds, mostly about building.

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