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Justin Poehnelt

Justin Poehnelt

Founder & CTO, Helen's Foundry

Founder and CTO at Helen's Foundry since May 2026, with a decade of experience in machine learning and AI agent infrastructure. Previously at Google and Descartes Labs.

Background

I'm the founder and CTO of Helen's Foundry. Google fired me in April 2026. I have a decade of experience in machine learning and AI agent infrastructure, including work as a Senior Developer Relations Engineer at Google on the Google Workspace and Google Maps Platform teams and as a Founding Engineer at Descartes Labs.

Recently, I architected the open-source Google Workspace CLI in Rust, built entirely via AI agents. It reached 31k+ stars and #1 on Hacker News. I've also built petabyte-scale Kubernetes systems, visual search engines over billions of satellite images, and embedded Rust firmware with custom LoRa mesh networking for endurance races.

Before Google, I worked with geospatial data at Descartes Labs and the U.S. Geological Survey, building data platforms and working with satellite imagery at scale. I coauthored research on visual search over billions of aerial and satellite images.

At Helen's Foundry, I lead development of the bitemporal graph architecture, verification engine, and MCP integrations. We connect strategy and decisions to the tickets and code agents work on. An agent can pass every test while implementing a ticket whose premise has changed. We're building Helen's Foundry to catch that.

Building tools for agents

I write about designing CLIs for AI agents and the tradeoffs in wrapping APIs with MCP. I want agents to inspect the interfaces they use and check the results of their work.

In my native Rust editor for fiction writers, I embedded an MCP server so agents could enter text, inspect diagnostics, and capture the rendered window. My Gmail-triage experiment explores how to divide context and permissions among agents, including where instructions fall short of enforced controls.

Education

  • Northern Arizona University: B.S. Computer Science (2013–2016)
  • University of Wisconsin–La Crosse: B.S. Economics and Finance (dual majors)

Open source

I'm a maintainer and contributor to several open-source projects across the Google ecosystem and beyond:

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Speaking & content

Beyond code

When I'm not coding, I'm usually running long distances in the mountains of Colorado. I've completed 35+ ultramarathons including multi-day events like the Moab 240 and Cocodona 250. Notable results include 1st at the Ute 100 50-miler, 2nd at Creede 100, and 2nd at Deadman Peaks. I serve on the boards of the Falls Creek Ranch Association and Falls Creek Wildlands and Trails.

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