# Agents write most of Modal’s merged code

Markdown copy of https://realalpha.app/s/agents-write-most-of-modals-merged-code/ on Real Alpha, the best minutes from long interviews with the people building AI. Cite and link the page, not this copy.

- Speaker: [Erik Bernhardsson](https://realalpha.app/builders/erik-bernhardsson/) · Erik Bernhardsson is co-founder and CEO of Modal. · Co-founded Modal, the high-performance cloud for AI teams; previously led Spotify's music recommendation and data infrastructure teams.
- Host: [Jacob Effron](https://realalpha.app/people/jacob-effron/) · AI Investor, Redpoint Ventures · Growth investor in Abridge, Ramp and Physical Intelligence; ex-Flatiron Health.
- Host: Pat Chase · AI Investor, Redpoint Ventures
- Show: Unsupervised Learning
- Episode: [Modal CEO on the Future of Inference, the Chaos of the GPU Market & Origins of the Sandbox Bet](https://realalpha.app/v/HJDekXH-h5c/), Oct 28, 2026
- Moment: 27:01 to 30:20 of the episode (3 min), playing on https://realalpha.app/s/agents-write-most-of-modals-merged-code/; the episode from there: https://realalpha.app/v/HJDekXH-h5c/?t=1621

## Quote

> “I mean, I think probably at this point, **95% of the lines of code** that gets merged at Modal is probably written by agents to some extent.”
> — [Erik Bernhardsson](https://realalpha.app/builders/erik-bernhardsson/) at [27:43](https://realalpha.app/v/HJDekXH-h5c/?t=1663) · Unsupervised Learning

## Takeaways

1. Agents contribute to about 95% of merged code at Modal.
2. Senior engineers use agents to execute ideas faster.
3. Infrastructure work still needs human oversight.

## About this segment

Erik Bernhardsson estimates agents contribute to about 95% of Modal’s merged code, with senior engineers among the fastest adopters. Humans still supervise agents on reliability and scale.

From “Modal CEO on the Future of Inference, the Chaos of the GPU Market & Origins of the Sandbox Bet”, Oct 28, 2026. [Watch the full episode](https://realalpha.app/v/HJDekXH-h5c/)

## Transcript

Transcribed by machine (Whisper) from the episode’s audio, so a word may be off here and there.

[27:04](https://realalpha.app/v/HJDekXH-h5c/?t=1624) How much has, you know, you guys were building the company pre-ChatGPT and then, you know, post-ChatGPT moment. How much has that changed, you know, maybe on the product side, you know, what you guys were doing, but then also when you were thinking about building and the velocity that you can ship software at? Yeah, I mean, we've always benefited from, you know, being quite well positioned at a time where like AI kind of blew up.

[27:30](https://realalpha.app/v/HJDekXH-h5c/?t=1650) And that's been incredible to see. And we're powering so many different AI applications today that I had no idea would exist four years ago, five years ago when we started Modal. So that's been kind of incredible. And like you said, software in itself is also... How we build software has changed a lot. People write... I mean, I think probably at this point, 95% of the lines of code that gets merged at Modal is probably written by agents to some extent.

[27:54](https://realalpha.app/v/HJDekXH-h5c/?t=1674) Infrastructure still, I feel like relies a lot on... Agents are kind of good at it. I've actually been on a team. Like the last few days, like building or last few months, actually, like writing like an insane amount of code using agents. And like, it's kind of incredible, like what they can build, but like you kind of still need humans to like supervise them quite a lot. And like, you know, infrastructure has a lot of tail risks around the reliability and taking and making sure that things scale and like stuff like that.

[28:19](https://realalpha.app/v/HJDekXH-h5c/?t=1699) So at least for now, I think software engineers are pretty safe. And I think we still benefit from having incredibly good engineers that can supervise these agents, I think probably for the next few years. Another thing I think has been kind of interesting to see is like, actually, like, I think the adoption pattern is actually the opposite of what I would have expected. Like, I thought it would be the junior people that would adopt agents the most.

[28:39](https://realalpha.app/v/HJDekXH-h5c/?t=1719) I've actually seen almost the other way around. It's like the very senior people, because for them, it's like giving them like 10 interns. Like, they've been kind of constrained by like typing speed for a long time, but they have all these ideas in their heads. And I think using agents, now they can get it like they can get it out like much faster. They're really good at building a test suite. Like, you know, give the agents like, here's an extensive test suite.

[28:58](https://realalpha.app/v/HJDekXH-h5c/?t=1738) It implements all of, you know, the POSIX standard for file systems. Now go write a new file system. And it just goes on, like, just writes a file system and takes, like, you know, three days to do it. So we've seen, you know, some of the very senior engineers, like, go, like, complete agent maxing. And I don't know. I mean, it's kind of incredible, like, what you can do with agents. You can move very fast with them.

[29:18](https://realalpha.app/v/HJDekXH-h5c/?t=1758) At the end of the day, it seems like humans are still safe as software engineers for the next few years. I don't know. We'll see. How have you found the velocity of shipping software has changed what you guys need to do with code review or CICD or deployment? Have those pieces of your development lifecycle changed at all? I think a little bit. I think we're coming up against some of those constraints. We've had to spend a lot more time on CICD. Even long before agents, I was a CTO for many years. I was always obsessed with CICD. It's very, very important to figure out.

[29:50](https://realalpha.app/v/HJDekXH-h5c/?t=1790) So in that sense, I don't know if it's changed my view as you really need to have automated deployments, automated tasks, all these things. Now, by the way, agents are pretty good at writing tests, too. They weren't like a year ago. So I don't know if we've necessarily yet run up against the foundational limits. But I mean, Anthropic, a couple of days ago, they announced they're moving off Git, I believe, or at least GitHub.

[30:14](https://realalpha.app/v/HJDekXH-h5c/?t=1814) We might run up against those limits at some point when we have 10x the amount of commits every day.