line of code because we aligned on everything ahead of time. This brings us to the agentic software factory. Uh every company and their mother is talking about how they built a coding agent factory that ships 75% of their code now. Uh literally everybody. Uh and so if we look at the software factory from 2022, uh we just replace someone builds the thing with an agent builds the thing. And we have an orchestration and a harness and a sandbox and a model and computer use and I'm not going to get into like the details of that. You can watch 100 talks about that this week, I'm sure. Um but now the building part takes minutes or hours, but this human part still takes hours or days if you're going to review the code and you're going to test the changes. And so we bring in agentic code review. We bring in agentic regression testing, uh and it makes this part faster, but it's probably still the bottleneck. But we can do more loops here. Why not? Let's do some more loops. So we can route all incidents straight into the factory. Why does someone need to get woken up uh and try to fix it when they could just wake up to a pull request and uh maybe that fixes the issue for you. You can take all the user feedback and just stick it straight into the factory so that people ask for stuff and it gets built. And now your only job is how much things can you stuff into the queue of stuff to do and how fast can you review and test the changes? Which brings us of course to, I'm sure you know, the lights off software factory where basically Dentsu Bureau coined this is we no longer read the code. We say, "You know what? This is going great. That code review thing? No, thanks. We're just not going to do that anymore." Uh and we invest into all these other parts of the system. Your your testing, your monitoring, your rollout, everything else. We just write more code and build those systems better. And now our job really is just how much how much stuff can we ask the agent to build? I am going to posit that this does not work. Uh and this is why software factories fail. Um as as an aside, what I'm going to say has nothing to do with vibe coding. So Addy had this uh great post. I'm going to just going to literally take his quote verbatim. A developer vibe coding a side project a dozen people will ever run, and a team keeping a 10-year-old enterprise system alive for another quarter share almost no constraints worth naming. And most of what you hear on the internet is one of these groups of people telling the other group of people how to live their lives. So, if you love vibe coding, please go on. Um at Human Layer, what we care about is how do we help people solve hard problems in complex codebases. Um we use the word brownfield a lot, which historically has meant like some 10-year-old Java thing. I actually think agents really start to struggle after maybe 3 to 6 months, especially with the pace at which we can ship now. Um you can ask me how I know this, and I will tell you that it is because in July 2025, we tried this. We went full lights off, and uh if you have tried this seriously for a number of months, you probably found at least one issue that the agent couldn't solve. Even with your most advanced prompting, you do research, you do reproductions, you just you have to go and dig into that codebase that you stopped reading 3 months ago to try to figure out what's broken. And in the meantime, your site was down, your users were pissed, and you were If you were like me, you were probably miserable reading all this slop code that you let slip into your system. And what I want to get to is basically models have a shortcoming. Um they can't maintain and improve codebase quality over time, not without a a decent amount of human steering. Um and when I say maintainability, I'm basically talking about issues like it becomes really, really hard to make a change in one part of the codebase without breaking other parts of the codebase. This is Martin Fowler's shotgun surgery, textbook code smell. Um I'm not going to say much more about maintainability. There's a bunch of books that you can go read about it. In fact, John Osterhout is actually here speaking this week, so you can go ask him in person about the philosophy of software design if you want to. Um but it brings us to this question of like why can't models do software maintainability? Um and you may also be saying, but Dex, you know, surely the models have gotten much better since then. Um they've gotten better in some ways, but they're still about the same in others. Um if you want to solve one-off problems or vibe code a new marketing side, yes, they got way better since 2025 and 2024. But as far as improving code base quality, I think uh they have not gotten much better. Now, I cannot prove this because there are no good benchmarks for a model's ability to maintain code base quality, and I'll get into like where we're going with that. Um, but if you've worked with coding agents for a while, a lot of people are posting about this. It's just like you probably have this vibe that they they generally make things worse over time and make the code base harder to work in.