Uploaded April 2026 | Updated September 2026, 2 weeks ago
Mario Zechner is the creator of Pi, a minimalist, self-modifying AI coding agent, that is the foundation upon which OpenClaw (created by Peter Steinberger) is built. Meanwhile, Armin Ronacher is the creator of Flask, and a longtime user of Pi. The pair are also friends.
I sat down with Mario and Armin for the latest episode of the Pragmatic Engineer Podcast for an interesting conversation about AI and their reservations about it – even though both are heavily invested in building AI-powered tools.
Mario explains why he built Pi, and gives his take on why it has become so popular. Armin walks us through how he uses AI tools, including building a game with Pi, and why he always puts human judgment firmly at the heart of his approach.
We cover the risks of over-automation, the limits of agentic workflows, and why strong engineers with informed judgment still matter. We also get into the challenges of working with code written by non-engineers, and whether open source can withstand a tidal wave of agent-generated code.
—
*Brought to you by our season partners:*
• Statsig — The unified platform for flags, analytics, experiments, and more. statsig.com/pragmatic
• Sonar – The makers of SonarQube, the industry standard for automated code review. https://www.sonarsource.com/pragmatic/?utm_medium=paid&utm_source=pragmaticengineer&ut[…]egory=Paid&s_source=Paid%20Other&s_origin=pragmaticengineer
• WorkOS – Everything you need to make your app enterprise ready. workos.com
—
*The Pragmatic Engineer deepdives relevant for this episode:*
• The impact of AI on software engineers in 2026: key trends newsletter.pragmaticengineer.com/p/the-impact-of-ai-on-software-engineers-2026
• Cycles of disruption in the tech industry newsletter.pragmaticengineer.com/p/cycles-of-disruption-in-the-tech
• The AI engineering stack newsletter.pragmaticengineer.com/p/the-ai-engineering-stack
• The creator of OpenClaw: "I ship code that I don't read" newsletter.pragmaticengineer.com/p/the-creator-of-clawd-i-ship-code
• What is inference engineering? Deepdive newsletter.pragmaticengineer.com/p/what-is-inference-engineering
—
*Where to find Mario Zechner:*
• X: https://x.com/badlogicgames
• LinkedIn: linkedin.com/in/mariozechner
• Website: https://mariozechner.at
*Where to find Armin Ronacher:*
• X: https://x.com/mitsuhiko
• LinkedIn: linkedin.com/in/arminronacher
• Website: https://mitsuhiko.at
• Blog: lucumr.pocoo.org
—
*In this episode, we cover:*
(00:00) Intro
(07:30) How Mario, Armin, and Peter Steinberger met
(15:15) How 30 dev teams use AI agents: learnings
(21:50) The importance of judgment
(24:26) Challenges when non-engineers write code
(28:30) Downsides of over-automation
(32:18) Pi
(48:09) OpenClaw + Pi
(50:54) “Clankers”
(57:32) Open source and AI
(1:00:22) Complexity as the enemy
(1:02:50) Building an AI-native startup
(1:11:52) “Slow the F down”
(1:16:40) MCPs vs. CLI
(1:25:03) Predictions and staying up to date
—
See the transcript and other references from the episode at newsletter.pragmaticengineer.com/podcast
—
Production and marketing by penname.co/.
Mario Zechner is the creator of Pi, a minimalist, self-modifying AI coding agent, that is the foundation upon which OpenClaw (created by Peter Steinberger) is built. Meanwhile, Armin Ronacher is the creator of Flask, and a longtime user of Pi. The pair are also friends.
I sat down with Mario and Armin for the latest episode of the Pragmatic Engineer Podcast for an interesting conversation about AI and their reservations about it – even though both are heavily invested in building AI-powered tools.
Mario explains why he built Pi, and gives his take on why it has become so popular. Armin walks us through how he uses AI tools, including building a game with Pi, and why he always puts human judgment firmly at the heart of his approach.
We cover the risks of over-automation, the limits of agentic workflows, and why strong engineers with informed judgment still matter. We also get into the challenges of working with code written by non-engineers, and whether open source can withstand a tidal wave of agent-generated code.
—
*Brought to you by our season partners:*
• Statsig — The unified platform for flags, analytics, experiments, and more. statsig.com/pragmatic
• Sonar – The makers of SonarQube, the industry standard for automated code review. https://www.sonarsource.com/pragmatic/?utm_medium=paid&utm_source=pragmaticengineer&ut[…]egory=Paid&s_source=Paid%20Other&s_origin=pragmaticengineer
• WorkOS – Everything you need to make your app enterprise ready. workos.com
—
*The Pragmatic Engineer deepdives relevant for this episode:*
• The impact of AI on software engineers in 2026: key trends newsletter.pragmaticengineer.com/p/the-impact-of-ai-on-software-engineers-2026
• Cycles of disruption in the tech industry newsletter.pragmaticengineer.com/p/cycles-of-disruption-in-the-tech
• The AI engineering stack newsletter.pragmaticengineer.com/p/the-ai-engineering-stack
• The creator of OpenClaw: "I ship code that I don't read" newsletter.pragmaticengineer.com/p/the-creator-of-clawd-i-ship-code
• What is inference engineering? Deepdive newsletter.pragmaticengineer.com/p/what-is-inference-engineering
—
*Where to find Mario Zechner:*
• X: https://x.com/badlogicgames
• LinkedIn: linkedin.com/in/mariozechner
• Website: https://mariozechner.at
*Where to find Armin Ronacher:*
• X: https://x.com/mitsuhiko
• LinkedIn: linkedin.com/in/arminronacher
• Website: https://mitsuhiko.at
• Blog: lucumr.pocoo.org
—
*In this episode, we cover:*
(00:00) Intro
(07:30) How Mario, Armin, and Peter Steinberger met
(15:15) How 30 dev teams use AI agents: learnings
(21:50) The importance of judgment
(24:26) Challenges when non-engineers write code
(28:30) Downsides of over-automation
(32:18) Pi
(48:09) OpenClaw + Pi
(50:54) “Clankers”
(57:32) Open source and AI
(1:00:22) Complexity as the enemy
(1:02:50) Building an AI-native startup
(1:11:52) “Slow the F down”
(1:16:40) MCPs vs. CLI
(1:25:03) Predictions and staying up to date
—
See the transcript and other references from the episode at newsletter.pragmaticengineer.com/podcast
—
Production and marketing by penname.co/.
