Armin Ronacher's Thoughts and Writings

Mario and Earendil

written on April 08, 2026

Today I’m very happy to share that Mario Zechner is joining Earendil.

First things first: I think you should read Mario’s post. This is his news more than it is ours, and he tells his side of it better than I could. What I want to do here is add a more personal note about why this matters so much to me, how the last months led us here, and why I am so excited to have him on board.

Last year changed the way many of us thought about software. It certainly changed the way I did. I spent much of 2025 building, probing, and questioning how to build software, and in many more ways what I want to do. If you are a regular reader of this blog you were along for the ride. I wrote a lot, experimented a lot, and tried to get a better sense for what these systems can actually do and what kinds of companies make sense to build around them. There was, and continues to be, a lot of excitement in the air, but also a lot of noise. It has become clear to me that it’s not a question of whether AI systems can be useful but what kind of software and human-machine interactions we want to bring into the world with them.

That is one of the reasons I have been so drawn to Mario’s work and approaches.

Pi is, in my opinion, one of the most thoughtful coding agents and agent infrastructure libraries in this space. Not because it is trying to be the loudest or the fastest, but because it is clearly built by someone who cares deeply about software quality, taste, extensibility, and design. In a moment where much of the industry is racing to ship ever more quickly, often at the cost of coherence and craft, Mario kept insisting on making something solid. That matters to me a great deal.

I have known Mario for a long time, and one of the things I admire most about him is that he does not confuse velocity with progress. He has a strong sense for what good tools should feel like. He cares about details. He cares about whether something is well made. And he cares about building in a way that can last. Mario has been running Pi in a rather unusual way. He exerts back-pressure on the issue tracker and the pull requests through OSS vacations and other means.

The last year has also made something else clearer to me: these systems are not only exciting, they are also capable of producing a great deal of damage. Sometimes that damage is obvious; sometimes it looks like low-grade degradation everywhere at once. More slop, more noise, more disingenuous emails in my inbox. There is a version of this future that makes people more distracted, more alienated, and less careful with one another.

That is not a future I want to help build.

At Earendil, Colin and I have been trying to think very carefully about what a different path might look like. That is a big part of what led us to Lefos.

Lefos is our attempt to build a machine entity that is more thoughtful and more deliberate by design. Not an agent whose main purpose is to make everything a little more efficient so that we can produce even more forgettable output, but one that can help people communicate with more care, more clarity, and joy.

Good software should not aim to optimize every minute of your life, but should create room for better and more joyful experiences, better relationships, and better ways of relating to one another. Especially in communication and software engineering, I think we should be aiming for more thought rather than more throughput. We should want tools that help people be more considerate, more present, and more human. If all we do is use these systems to accelerate the production of slop, we will have missed the opportunity entirely.

This is also why Mario joining Earendil feels so meaningful to me. Pi and Lefos come from different starting points. There was a year of distance collaboration, but they are animated by a similar instinct: that quality matters, that design matters, and that trust is earned through care rather than captured through hype.

I am very happy that Pi is coming along for the ride. Me and Colin care a lot about it, and we want to be good stewards of it. It has already played an important role in our own work over the last months, and I continue to believe it is one of the best foundations for building capable agents. We will have more to say soon about how we think about Pi’s future and its relationship to Lefos, but the short version is simple: we want Pi to continue to exist as a high-quality, open, extensible piece of software, and we want to invest in making that future real. As for our thoughts of Pi’s license, read more here and our company post here.

This entry was tagged ai and thoughts