YouSaid · the spoken record

Boris Cherny

lines on the record: 116
first: 2026-02-19
most recent: 2026-02-19
sittings or episodes: 1
sources: podcast

Every line below is reproduced as it was said and linked to the record it came from. Nothing here is summarised or generated. Directory · Search · Corrections

“Find me on threads or on Twitter. That's the easiest place. And please just tag me on stuff. Send bugs, send feature requests. What's missing? What can we do to make the products better? What do you want? I love, love hearing it.”
2026-02-19 · Lenny's Podcast · Head of Claude Code: What happens after coding is solved | Boris Cherny · IDENTIFIED FROM THE TRANSCRIPT · source
“And at some point, I just kind of got bored and I ran out of ideas for a few hours. I was like, okay, what do I want to do next? And so I opened Twitter. I saw some people tweeting about quad code. And then I just started responding. And then I was like, okay, maybe actually a thing I should do is just like look for people look for bugs that people have. Maybe people have bugs or kind of feedback they have. And so kind of introduce myself, ask for people had a bunch of bugs and feedback. And I think they were kind of surprised by the pace at which we're able to address feedback nowadays. For me, it's just so normal. Like if someone has a bug, like I can probably fix it within a few minutes because I just sort of quad. And as long as the description is good, it will just go and do it. And then I'll go do something else and answer the next thing. But I think for a lot of people, it was pretty surprising. So it was really cool. And yeah, the experience on Twitter has been pretty great. It's been awesome just engaging with people and seeing what people want, hearing about bugs, hearing about features.”
2026-02-19 · Lenny's Podcast · Head of Claude Code: What happens after coding is solved | Boris Cherny · IDENTIFIED FROM THE TRANSCRIPT · source
“Oh, yeah, yeah, yeah. I started using Twitter because I was born. So my wife and I were traveling around in Europe for December. We're just kind of nomading around. We went to Copenhagen, went to a few different countries. And for me, it was just like a coding vacation. So every day I was coding. And that's my favorite kind of vacation, just to just code all day. It's the best”
2026-02-19 · Lenny's Podcast · Head of Claude Code: What happens after coding is solved | Boris Cherny · IDENTIFIED FROM THE TRANSCRIPT · source
“So, for a long time, I used threads exclusively because I actually helped build threads a little bit back in the day And also, just like the design, it's like a very clean product. I just really like that. I started using threads because actually I was bored. So in December, I was in Europe. I started using Twitter.”
2026-02-19 · Lenny's Podcast · Head of Claude Code: What happens after coding is solved | Boris Cherny · IDENTIFIED FROM THE TRANSCRIPT · source
“Common sense I think a lot of the failures that I see in, especially in a work environment, is people just failing to use common sense. Like they follow a process without thinking about it. They just do a thing without thinking about it, or they're working on a product that's not a good product or not a good idea. And they're just following the momentum and not thinking about it. I think the best results that I see are people thinking from first principles and just developing their own common sense. Like if something smells weird, then it's probably not a good idea. So I think just this is the single advice that I give to coworkers more than anything too.”
2026-02-19 · Lenny's Podcast · Head of Claude Code: What happens after coding is solved | Boris Cherny · IDENTIFIED FROM THE TRANSCRIPT · source
“So, actually, one of our PMs used that as a way to evaluate co-work before we released it. And I think at the point where co-work was able to do like 48 out of the 50, they were like, okay, it's pretty good.”
2026-02-19 · Lenny's Podcast · Head of Claude Code: What happens after coding is solved | Boris Cherny · IDENTIFIED FROM THE TRANSCRIPT · source
“Yeah, I think a lot of this was also, some of this was also inspired by you, Lenny. You had this post about it was like 50 non-technical use cases for Kwakote or something like this.”
2026-02-19 · Lenny's Podcast · Head of Claude Code: What happens after coding is solved | Boris Cherny · IDENTIFIED FROM THE TRANSCRIPT · source
“The third thing is just run a bunch of clods in parallel so it can co work. You can have as many tasks running as you want. So it's like start one task, you know, I have this project management thing running, then I'll have it do something else, then something else, and I'll kick these off. And then I just go get a coffee while it runs.”
2026-02-19 · Lenny's Podcast · Head of Claude Code: What happens after coding is solved | Boris Cherny · IDENTIFIED FROM THE TRANSCRIPT · source
“Exactly, exactly. For people that are just running to use cowork, the thing I recommend is so you download the quad desktop app, you go to the coworkets right next to the code tab. The thing that I recommend doing is like start by having it use a tool. So like clean up your desktop or summarize your email or something like this or respond to the top three emails. It actually just responds to emails for me now too. The second thing is connect tools. So like if you connect like if you say look at my top emails and then sends fact messages or put them in a spreadsheet or something or for example like I use it for all my project management. So we have a single spreadsheet for the whole team. There's like a rope or engineer every week everyone fills out a status. And every Monday co-work just goes through and it messages every engineer on Slack that hasn't filled out their status. And so I don't have to do this anymore. And this is just one prompt. It'll do everything.”
2026-02-19 · Lenny's Podcast · Head of Claude Code: What happens after coding is solved | Boris Cherny · IDENTIFIED FROM THE TRANSCRIPT · source
“Yeah, exactly, exactly. And it actually just kind of works. Like we tried this experiment a year ago and it didn't really work because the model wasn't ready, but now it actually just works. And it's amazing. I think a lot of people just don't really understand what this is because they haven't used the agent before. And it just feels very, very similar to me to quad code a year ago. But like I said, it's just growing much faster than quadcode did in the early days. So I think it's starting to break through a bit.”
2026-02-19 · Lenny's Podcast · Head of Claude Code: What happens after coding is solved | Boris Cherny · IDENTIFIED FROM THE TRANSCRIPT · source
“Gonna like chill a little bit and just say co work because this is legitimately the one product that's been pretty life changing for me just because I have a running all the time and the Chrome integration in particular is just really excellent So it's been like it paid a traffic fine for me it like canceled a couple of subscriptions for me just like the amount of like tedious work it gets out of the way is awesome I also don't know if it's a product, but maybe I'll also another podcast that I really love obviously besides besides Lenny is obviously Yeah, it's the acquired podcast by Ben and David. It's just like, it's super awesome. I feel like the way that they get into business history and bring it alive is really, really good. And I would start with a Nintendo episode. If you haven't listened to it.”
2026-02-19 · Lenny's Podcast · Head of Claude Code: What happens after coding is solved | Boris Cherny · IDENTIFIED FROM THE TRANSCRIPT · source
“So, I actually don't really watch TV or movies. I just don't really have time these days. I did watch, I'm going to bring up another Seishan Lu, but the three-body problem series on Netflix, I really loved. I thought that was like a great rendition of the book series.”
2026-02-19 · Lenny's Podcast · Head of Claude Code: What happens after coding is solved | Boris Cherny · IDENTIFIED FROM THE TRANSCRIPT · source
“I think for me, this was like the reason that I joined Anthropic, actually, because like I said, I was looking in this rural place. I was thinking these long time skills because everything is just so slow out there, at least compared to SF. And just like all the things that you do are based around the seasons and it's based around this food that takes many, many months. That's the way that kind of like social events are organized. That's the way you kind of organize your time. You go to the farmer's market and it's like it's persimmon season. And you know that because there's like 20% vendors. And then the next week the season is done and it's like grape season. And you kind of see this. So it's like these kind of long time skills. And I was also reading a bunch of sci-fi at the time. And just like being in this moment, I was like, you know, just thinking about these a long time scales. I know how this thing can go. And I just felt like I had to contribute to it going a little bit better. And that's actually why I ended up at Ant. And Ben Manos was also a big part of that too.”
2026-02-19 · Lenny's Podcast · Head of Claude Code: What happens after coding is solved | Boris Cherny · IDENTIFIED FROM THE TRANSCRIPT · source
“Liked his short stories even more. So Wandering Earth is one of the short story collections, and he just has some really, really amazing stories. And it's also just quite interesting to see Chinese sci-fi because it has a very different perspective than Western sci-fi, kind of the way that at least he as a writer thinks about it. So it's just really, really interesting to read and just beautifully written.”
2026-02-19 · Lenny's Podcast · Head of Claude Code: What happens after coding is solved | Boris Cherny · IDENTIFIED FROM THE TRANSCRIPT · source
“Oh, amazing, amazing. Okay, second one is Accelerondo by Strauss. This is probably my big genre is sci-fi, like probably sci-fi in fiction. Excel Ronda was just this incredible book, and it's just so fast-paced. The pace gets faster and faster and faster. And I just feel like it captures the essence of this moment that we're in more than any other book that I've read, just the speed of it. And it starts as liftoff is starting to happen and starting to approach the singularity. And it ends with this collective lobster consciousness orbiting Jupiter. And this happens over the span of a few decades or something. So the pace is just incredible. I really love it. Maybe I'll do one more book. The Wandering Earth, Wandering Earth by Sishin Lu. So he's the guy that did three body problem. I think a lot of people know him for that. Actually, I think three body problem was awesome, but I actually.”
2026-02-19 · Lenny's Podcast · Head of Claude Code: What happens after coding is solved | Boris Cherny · IDENTIFIED FROM THE TRANSCRIPT · source
“I'm a big reader. I would start with a technical book. One, it is functional programming in Scala. This is the single best technical book I've ever read. It's very weird because you're probably not going to use Scala. And I don't know how much this matters in the future now. But there's this just elegance to functional programming and thinking in types. And this is just the way that I code and the way that I can't stop thinking about coding. So you could think of it as a historical artifact. You could think of it as something that will level you up.”
2026-02-19 · Lenny's Podcast · Head of Claude Code: What happens after coding is solved | Boris Cherny · IDENTIFIED FROM THE TRANSCRIPT · source
“Yeah, yeah, yeah. It's crazy. And I mean, like, the way that quad code has kept growing is honestly just the users. So many people use it. They're so passionate about it. They fall in love with the product. And then they tell us about stuff that doesn't work, stuff that they want. And so like the only reason that it keeps improving is because everyone is using it. Everyone is talking about it. Everyone keeps giving feedback. And this is just the single most important thing. And, you know, for me, this is the way that I love to spend my days just talking to users and making it better for them.”
2026-02-19 · Lenny's Podcast · Head of Claude Code: What happens after coding is solved | Boris Cherny · IDENTIFIED FROM THE TRANSCRIPT · source
“Most of the world still does not use quad code. Most of the world still does not use AI. So it just feels like this is 1% done and there's so much more to go.”
2026-02-19 · Lenny's Podcast · Head of Claude Code: What happens after coding is solved | Boris Cherny · IDENTIFIED FROM THE TRANSCRIPT · source
“Yeah, I think I would just like to underscore anthropic since the beginning, this idea of starting at coding, then getting to tool use, then getting to computer use has just been the way that we think about things. And this is the way that we know the models are going to develop or the way that we want to build our models. And it's also the way that we get to learn about safety, study it, and improve it the most. So, you know, everything that's happening right now around just like quot code becoming this huge multibillion dollar business. And now all of my friends use Quad Code and they just text me about it all the time. So just like, you know, this thing getting kind of big. And in some ways, it's a total surprise because this isn't kind of the, we didn't know that it would be this product. We didn't know that it would start in a terminal or anything like this. But in some ways, it's just totally unsurprising because this has been our belief as a company for a long time. At the same time, it just feels still very early.”
2026-02-19 · Lenny's Podcast · Head of Claude Code: What happens after coding is solved | Boris Cherny · IDENTIFIED FROM THE TRANSCRIPT · source
“This was this interesting thing where it teaches you to think on these long time skills that's just very different than engineering. Because a batch of white measles takes like at least three months to make. And our red miso is like two, three, four years. You just have to be very patient. You kind of mix it up and then you just like wet its it. You have to be very, very patient. So the thing that I love about it is just thinking in these long time scales. And yeah, I think post-AGI or if I was an edanthropic, I'd probably be making me so.”
2026-02-19 · Lenny's Podcast · Head of Claude Code: What happens after coding is solved | Boris Cherny · IDENTIFIED FROM THE TRANSCRIPT · source
“So before I joined Anthropic, I was actually living in rural Japan, and it was like a totally different lifestyle. I was like the only engineer in the town. I was the only English speaker in the town. It was just like a totally different vibe. Like a couple of times a week, I would like a bike to the farmer's market. And, you know, you like bike by rice patties and stuff. It was just like a totally different speed than just complete opposite of San Francisco. One of the things that I really liked is a way that we got to know our neighbors and we kind of built friendships is by trading like pickles. So in the town where we lived, it was actually everyone made miso. Everyone made pickles. And so I actually got decently good at making miso. And I made a bunch of batches. And this is something that I still make.”
2026-02-19 · Lenny's Podcast · Head of Claude Code: What happens after coding is solved | Boris Cherny · IDENTIFIED FROM THE TRANSCRIPT · source
“Yeah, I actually haven't really used it, but I think I did use it maybe when it came out. It looked a lot like quad code to me, so that was kind of flattering. I think it's actually good, you know, to have more competition because people should get to choose and hopefully it forces all of us to do an even better job. Honestly, for our team, though, we're just focused on solving the problems that users have. So for us, we don't spend a lot of time looking at competing products. We don't really try the other products. You want to be aware of them and you want to know they exist. But for me, I just, I love talking to users. I love making the product better. I love just acting on feedback. So it's really just about building a good product.”
2026-02-19 · Lenny's Podcast · Head of Claude Code: What happens after coding is solved | Boris Cherny · IDENTIFIED FROM THE TRANSCRIPT · source
“And then maybe the third tip is just play around with different interfaces. I think a lot of people, when they think about Klatco, they think about a terminal. And of course we support every terminal, we support Mac, Windows, whatever terminal you might use, it works perfectly. But we actually support a lot of other form factors too. We have iOS and Android apps. We have a desktop app. The Slack integration. There's all sorts of things that we support. So I would just play around with these. And again, it's like every engineer is different. Everyone that's building is different. Just find the thing that feels right to you and use that. You don't have to use a terminal. It's the same cloud agent running everywhere.”
2026-02-19 · Lenny's Podcast · Head of Claude Code: What happens after coding is solved | Boris Cherny · IDENTIFIED FROM THE TRANSCRIPT · source
“And so for people that are in the terminal, it's just shift tab twice, and that gets you into plan mode. For people in the desktop app, there's a little button on web, there's a little button. It's coming pretty soon to mobile also. And we just launched it for the Slavic integration too. So Plan Mode is the second one. And essentially the model would just go back and forth with you once the plan looks good, then you let the model execute. I auto-accept edits after that because if the plan works good, it's just going to one-shot it. It'll get it right the first time almost every time with Opus 4.6.”
2026-02-19 · Lenny's Podcast · Head of Claude Code: What happens after coding is solved | Boris Cherny · IDENTIFIED FROM THE TRANSCRIPT · source
“The second one is use plan mode. I start almost all of my tasks in plan mode, maybe like 80%. And plan mode is actually really simple. All it is is we inject one sentence into the model's prompt to say, please don't write any code yet. That's it. There's actually nothing fancy going on. It's just the simplest thing.”
2026-02-19 · Lenny's Podcast · Head of Claude Code: What happens after coding is solved | Boris Cherny · IDENTIFIED FROM THE TRANSCRIPT · source
“A few tips that generally I find pretty useful. So, number one is just use the most capable model. Currently, that's open 4.6. I have maximum effort enabled always. The thing that happens is sometimes people try to use a less expensive model like Sonnet or something like this. But because it's less intelligent, it actually takes more tokens in the end to do the same task. And so it's actually not obvious that it's cheaper if you use a less expensive model. Often it's actually cheaper and less token intensive if you use the most capable model because it can just do the same thing much faster with less correction, less hand holding and so on. So that's the first step is just use the best model.”
2026-02-19 · Lenny's Podcast · Head of Claude Code: What happens after coding is solved | Boris Cherny · IDENTIFIED FROM THE TRANSCRIPT · source
“I will give a caveat, which is there's no one right way to use quad code. So I can share some tips, but honestly, this is a DevTool. Developers are all different. Developers have different preferences. They have different environments. So there's just so many ways to use these tools. There's no one right way. You sort of have to find your own path. Luckily, you can ask quotes. It's able to make recommendations. It can edit your settings. It kind of knows about itself. So it can help with that.”
2026-02-19 · Lenny's Podcast · Head of Claude Code: What happens after coding is solved | Boris Cherny · IDENTIFIED FROM THE TRANSCRIPT · source
“Before we started going off the rails, and you just really had to hold its hand through any kind of complicated task. But nowadays with Opus 4.6, on average, it'll run maybe 10, 30, 20, 30 minutes unattended. And I'll just start another clod and have it do something else. And, you know, like I said, I always have a bunch of quads running. And they can also run for hours or even days at a time. I think there were some examples where they ran for many weeks. And so I think over time, this is going to become more and more normal where the models are running for a very, very long period of time. And you don't have to sit there and babysit them anymore.”
2026-02-19 · Lenny's Podcast · Head of Claude Code: What happens after coding is solved | Boris Cherny · IDENTIFIED FROM THE TRANSCRIPT · source
“I think that's a good way to do it. Obviously, within an AI lab, we get to see the specifics that it gets better It's a little unfair, but we also try to talk about this. So, you know, like one of the ways that it's going to get better is it's going to get better and better at using tools and using computers. Is a bet that I would make. Another one is it's going to get better and better for running for a long period of time. This is a place, you know, like there's all sorts of studies about those. But if you just trace the trajectory, or maybe even like from”
2026-02-19 · Lenny's Podcast · Head of Claude Code: What happens after coding is solved | Boris Cherny · IDENTIFIED FROM THE TRANSCRIPT · source
“A lot of folks, especially people building startups, it's going to be uncomfortable because your product market won't be very good for the first six months. But if you build for the model six months out, when that model comes out, you're just going to hit the ground running and the product is going to click and start to work.”
2026-02-19 · Lenny's Podcast · Head of Claude Code: What happens after coding is solved | Boris Cherny · IDENTIFIED FROM THE TRANSCRIPT · source
“And for the very early versions of the product, they just wrote so little of my code because I didn't trust it. Because it was like Sonnet 3.5, then it was like 3.6 or forget, 3.5 new, whatever name we gave it. These models just weren't very good at coding yet. They were getting there, but it was still pretty early. So back then, the model used Git for me. It automated some things, but it really wasn't doing a huge amount of my coding. And so the bet with quad code was at some point the model gets good enough that it can just write a lot of the code. And this is the thing that we first started seeing with Opus 4 and Sonnet 4. And Opus 4 was our first kind of ASL3 class model that we released back in May. And we just saw this inflection because everyone started to use Quat Code for the first time. And that was kind of when our growth really went exponential. And like I said, it's kind of stayed there. So I think this is advice that I actually give.”
2026-02-19 · Lenny's Podcast · Head of Claude Code: What happens after coding is solved | Boris Cherny · IDENTIFIED FROM THE TRANSCRIPT · source
“And so these workflows are essentially a way that it's not a general model. It's putting the scaffolding around it. And in general, what we see is maybe scaffolding can improve performance maybe 10, 20 percent, something like this. But often these gains just get wiped out with the next model. So it's almost better to just wait for the next one And I think maybe this is a final principle and something that quad code, I think, got right in hindsight. From the very beginning, we bet on building for the model six months from now, not for the model of today.”
2026-02-19 · Lenny's Podcast · Head of Claude Code: What happens after coding is solved | Boris Cherny · IDENTIFIED FROM THE TRANSCRIPT · source
“The second one is maybe actually like a more even more general version of this principle is just the bitter lessons. And actually, for the quad core team, hopefully listeners have read this, but Rich Sutton had this blog post maybe 10 years ago called The Bitter Lesson. And it's actually a really simple idea. His idea was that the more general model will always outperform the more specific model. And I think for him, he was talking about self-driving cars and other domains like this. But actually, there's just so many corollaries to the bitter lesson. And for me, the biggest one is just always bet on the more general model. And over the long term, like don't try to use tiny models for stuff. Don't try to fine-tune. Don't try to do any of this stuff. There's some applications. There's some reasons to do this, but almost always try to bet on the more general model if you can, if you have that flexibility.”
2026-02-19 · Lenny's Podcast · Head of Claude Code: What happens after coding is solved | Boris Cherny · IDENTIFIED FROM THE TRANSCRIPT · source
“I'd probably share a few more things. So, one is don't try to box the model in. I think a lot of people's instinct when they build on the model is they try to make it behave a very particular way. They're like, this is a component of a bigger system. I think some examples of this are people layering very strict workflows on the model, for example, to say, you must do step one, then step two, then step three, and you have this very fancy orchestrator doing this. But actually, almost always you get better results if you just give the model tools, you give it a goal, and you let it figure it out. I think a year ago you actually needed a lot of the scaffolding, but nowadays you don't really need it. So, you know, I don't know what to call this principle, but it's like, you know, like asks not what the model can do for you. Maybe it's something like this. Just think about how do you give the model the tools to do things. Don't try to overcurate it. Don't try to put it into a box. Don't try to give it a bunch of context up front. Give it a tool so that it can get the context it needs. You're just going to get better results.”
2026-02-19 · Lenny's Podcast · Head of Claude Code: What happens after coding is solved | Boris Cherny · IDENTIFIED FROM THE TRANSCRIPT · source
“But I kind of think about those like in the back in the, you know, my family is from the Soviet Union. I was born in Ukraine. And my grandpa was actually one of the first programmers in the Soviet Union. And he programmed using punch cards. And he told my mom growing up told these stories of, or she told these stories of when she was growing up, he would bring these punch cards home. And there was these big stacks of punch cards. And for her, she would draw all over them with crayons. And that was like her childhood memory. But for him, that was like his experience of programming. And he actually never saw the software transition. But at some point, it did transition to software. And I think there was probably this older generation of programmers that just didn't take software very seriously. And they would have been like, well, you know, it's not really coding. But I think this is a field that just has always been changing in this way.”
2026-02-19 · Lenny's Podcast · Head of Claude Code: What happens after coding is solved | Boris Cherny · IDENTIFIED FROM THE TRANSCRIPT · source
“I remember reading something. This was maybe like very early versions of ACM magazine or something where people were saying, no, it's not the same thing. This isn't really coding. They call it programming. I think coding is kind of a new word.”
2026-02-19 · Lenny's Podcast · Head of Claude Code: What happens after coding is solved | Boris Cherny · IDENTIFIED FROM THE TRANSCRIPT · source
“I kind of wonder if the people that used to code using punch cards or whatever, if you show them software, what they would have said.”
2026-02-19 · Lenny's Podcast · Head of Claude Code: What happens after coding is solved | Boris Cherny · IDENTIFIED FROM THE TRANSCRIPT · source
“I always have a bunch of agents running, so I got the moment I have like five agents running. And at any moment, like, you know, like I wake up and I store a bunch of agents. Like the first thing I did when I woke up is like, oh man, I really want to check this thing. So I opened up my phone, quad iOS app, code tab, you know, like agent do blah blah blah because I wrote some code yesterday and I was like, wait, did I do this right? I was like kind of double guessing something. And it was correct. But now it's just like so easy to do this. So I don't know. There is this little bit of anxiety maybe. I personally haven't really felt it just because I have agents running all the time. And I'm also just like not locked into a terminal anymore. Maybe a third of my code now is in the terminal, but also a third is using the desktop app. And then a third is the iOS app, which is just so surprising because I did not think that this would be the way that I code even in 2026.”
2026-02-19 · Lenny's Podcast · Head of Claude Code: What happens after coding is solved | Boris Cherny · IDENTIFIED FROM THE TRANSCRIPT · source
“The top internally. And so for cloud code, for example, we released an open source sandbox. And this is a sandbox. They can run the agent in. And it just makes sure that there are certain boundaries and it can't access like everything on your system. And we made that open source and it actually works with any agent, not just quad code, because we wanted to make it really easy for others to do the same thing. So this is just the same principle of race to the top. We want to make sure this thing goes well. And this is just the lever that we have.”
2026-02-19 · Lenny's Podcast · Head of Claude Code: What happens after coding is solved | Boris Cherny · IDENTIFIED FROM THE TRANSCRIPT · source
“That it is doing something a little bit deeper. And then the structures, the way to do this are cohesive now, where as the models get bigger, it's not just like a single neuron that corresponds to a concept. A single neuron might correspond to a dozen concepts. And if it's activated together with other neurons, this is called superposition. And together it represents this more sophisticated concept. And it's just something we're learning about all the time. And for anthropic, as we think about the way this space evolves, doing this in a way that is safe and good for the world is just, this is the reason that we exist. And this is the reason that everyone is anthropic. Everyone that is here, this is the reason why they're here. So a lot of this work we actually open source. We publish it a lot. And we publish very freely to talk about this just so we can inspire other labs that are working on similar things to do it in a way that's safe. And this is something that we've been doing for Cloud Code also. We call this the race to the”
2026-02-19 · Lenny's Podcast · Head of Claude Code: What happens after coding is solved | Boris Cherny · IDENTIFIED FROM THE TRANSCRIPT · source
“Yeah, you should at some point have Chris Ola on the podcast because he's just the industry expert on this. He invented this field of, we call it mechanistic interpretability. And the idea is at its core, what is your brain? What is it? It's like, it's a bunch of neurons that are connected. And so what you can do is in a human brain or an animal brain, you can study it at this kind of mechanistic level to understand what the neurons are doing. It turns out surprisingly, a lot of this does translate to models also. So model neurons are not the same as animal neurons, but they behave similarly in a lot of ways. And so we've been able to learn just a ton about the way these neurons work, about, you know, this layer or this neuron maps to this concept, how particular concepts are encoded, how the model does planning, how it thinks ahead. A long time ago, we weren't sure if the model is just predicting the next token or is doing something a little bit deeper. Now I think there's actually quite strong evidence.”
2026-02-19 · Lenny's Podcast · Head of Claude Code: What happens after coding is solved | Boris Cherny · IDENTIFIED FROM THE TRANSCRIPT · source
“For co work, it's pretty similar. The models in this new setting are doing these tasks that are not engineering tasks. It's an agent that's acting on your behalf. He looks good on alignment. It looks good on evals. We try to internally, it looks good. We try it with a few customers. It looks good. Now we have to make sure it's safe in the real world. And so that's why we released a little early. That's why we call it a research preview. But yeah, it's just constantly improving. And this is really the only way to make sure that over the long term, the model is aligned and it's doing the right things.”
2026-02-19 · Lenny's Podcast · Head of Claude Code: What happens after coding is solved | Boris Cherny · IDENTIFIED FROM THE TRANSCRIPT · source
“Important because it might look very good on these first two errors, but not great on the third one. We release cloud code really early because we wanted to study safety. And we actually used it within Anthropic for, I think, four or five months or something before we released it because we weren't really sure like this is the first agent that the first big agent that I think folks had released at that point was definitely the first coding agent that became broadly used. And so we weren't sure if it was safe. And so we actually had to study it internally for a long time before we felt good about that. And even since, you know, there's a lot that we've learned about alignment. There's a lot that we've learned about safety that we've been able to put back into the model, back into the product.”
2026-02-19 · Lenny's Podcast · Head of Claude Code: What happens after coding is solved | Boris Cherny · IDENTIFIED FROM THE TRANSCRIPT · source
“And in philanthropic as a safety lab, the other dimension of that is safety because when you think about model safety, there's a bunch of different ways to study it. Sort of the lowest level is alignment and mechanistic interpretability. So this is when we train the model, we want to make sure that it's safe. We at this point have pretty sophisticated technology to understand what's happening in the neurons, to trace it. And so, for example, if there's a neuron related to deception, we can't start to get to the point where we can monitor it and understand that it's activating. And so this is just, this alignment, this is mechanistic interpretability. It's like the lowest layer. The second layer is evals. And this is essentially a laboratory setting. The model is in a petri dish and you study it. And you put in the synthetic situation and just say, okay, like model, what do you do? And are you doing the right thing? Is it aligned? Does it safe? And then the third layer is seeing how the model behaves in the wild. And as the model gets more sophisticated, this becomes so important.”
2026-02-19 · Lenny's Podcast · Head of Claude Code: What happens after coding is solved | Boris Cherny · IDENTIFIED FROM THE TRANSCRIPT · source
“Than we think, so that we can get the feedback, so that we can talk to users, we can understand what people want, and that will shape where the product goes in the future.”
2026-02-19 · Lenny's Podcast · Head of Claude Code: What happens after coding is solved | Boris Cherny · IDENTIFIED FROM THE TRANSCRIPT · source
“And we're trying to figure out what do we do. And so for a few months, the team was exploring. They were trying all sorts of different options. And in the end, someone was just like, okay, what if we just take quad code and put it in the desktop app? And that's essentially the thing that worked. And so over 10 days, they just completely used quad code to build it. And coworkers is actually, there's this very sophisticated security system that's built in. And essentially these guardrails to make sure that the model kind of does the right thing. It doesn't go off the rails. So for example, we ship an entire virtual machine with it. And quad code just wrote all of this code. So we just have to think about, all right, how do we make this a little bit safer, a little more self-guided for people that are not engineers? It was fully implemented with Cloud Code. Took about 10 days. We launched it early. It was still pretty rough and it's still pretty rough around the edges. But this is kind of the way that we learn, both on the product side and on the safety side, is we have to release things a little bit earlier.”
2026-02-19 · Lenny's Podcast · Head of Claude Code: What happens after coding is solved | Boris Cherny · IDENTIFIED FROM THE TRANSCRIPT · source
“Yeah, it's funny quad code, like I said, when we released it, it was not immediately a hit. It became a hit over time. And there was a few inflection points. So one was Opus 4. It just really, really inflected. And then in November, it inflected, and it just keeps inflecting. The growth just keeps getting steeper and steeper and steeper every day. But for the first few months, it wasn't a hit. People used it, but a lot of people couldn't figure out how to use it. They didn't know what it was for. The model still wasn't very good. Co-work, when we released it, it was just immediately a hit. much more so than cloud code was early on. I think a lot of the credit honestly just goes to like Felix and Sam and Jenny and the team that built this is just an incredibly strong team. And again, the place co-worker came from is just this latent demand. We saw people using Cloud Code for these non-”
2026-02-19 · Lenny's Podcast · Head of Claude Code: What happens after coding is solved | Boris Cherny · IDENTIFIED FROM THE TRANSCRIPT · source
“Let's look at what the model is trying to do and make that a little bit easier. And so when we first started building Quad Code, I think a lot of the way that people approached designing things with LLMs is they kind of put the model in a box. And they were like, here's this application that I want to build. Here's the thing that I wanted to do, model. You're going to do this one component of it. Here's the way that you're going to interact with these tools and APIs and whatever. And for cloud code, we inverted that. We said the product is the model. We want to expose it. We want to put the minimal scaffolding around it, give it the minimal set of tools. So it can do the things. It can decide which tools to run. It can decide in what order to run them in. and so on. And I think a lot of this was just based on kind of latent demand of what the model wanted to do. And so in research, we call this being on distribution. You want to see what the model is trying to do in product terms, latent demand is just the same exact concept, but applied to a model.”
2026-02-19 · Lenny's Podcast · Head of Claude Code: What happens after coding is solved | Boris Cherny · IDENTIFIED FROM THE TRANSCRIPT · source
“You figured out how to open the terminal, which is a very engineering product. Even a lot of engineers don't want to use a terminal. It's just like the lowest level way to do your work. Just really, really kind of in the weeds of the computer. And so he figured out how to use the terminal. He downloaded Node.js. He downloaded quad code. And he was doing SQL analysis in a terminal. And it was crazy. And then the next week, all the data scientists were doing the same thing. So when you see people abusing the product in this way, using it in a way that it wasn't designed in order to do something that is useful for them, it's just such a strong indicator that you should just build a product and people are going to like that. It's something that's special purpose for that. I think now there's also this kind of interesting second dimension to latent demand. This is sort of the traditional framing is look at where people are doing, make that a little bit easier, empower them. The modern framing that I've been seeing in the last six months is a little bit different.”
2026-02-19 · Lenny's Podcast · Head of Claude Code: What happens after coding is solved | Boris Cherny · IDENTIFIED FROM THE TRANSCRIPT · source
“And for example, this is also where co-work came from. We saw that for the last six months or so, a lot of people using Cloud Code were not using it to code. There was someone on Twitter that was using it to grow tomato plants. There was someone else using it to analyze their genome. Someone was using it to recover photos from a corrupted hard drive. It was like wedding photos. There was someone that was using it for, I think they were using it to analyze an MRI. So there's just all these different use cases that are not technical at all. And it was just really obvious. Like people are jumping through hoops to use a terminal to do this thing. Maybe we should just build a product for them. And we saw this actually pretty early. Back in maybe May of last year, I remember walking into the office and our data scientist, Brendan, had a quad code on his computer. He just had a terminal up. And I was like, I was shocked. I was like, Brandon, what are you doing?”
2026-02-19 · Lenny's Podcast · Head of Claude Code: What happens after coding is solved | Boris Cherny · IDENTIFIED FROM THE TRANSCRIPT · source