Hey guys, welcome to Silicon Valley Girl. We are about to interview the founder of Duolingo.
Oh. Oh, no. No, no, no. Do not you. No, no, no. Do we have the actual founder?
Your employees are getting a little creative.
We pay that guy and he has his own personality. He just does what he wants.
AI is not going to take your job. Somebody using AI is going to take your job.
This is Luis Von Ahn, CEO of Duolingo. Recently, two of his employees built a chess course with AI in six months. No engineering background, no knowledge of the subject. It became the fastest growing course in the company. There are a lot of rumors large companies firing people. They say it's AI.
We have never done a layoff. Despite what the internet may think, it is important to continue hiring people because a single employee is just way more productive now than they used to be.
I'm going to name five professions and you're going to make some predictions. Gone in five years or not going anywhere?
There will be fewer and fewer.
Please, you told your team that nobody gets hired unless team proves AI can do the work first. Can you tell me how you actually track that? As a founder,
Our goal here is to use AI to benefit our users. Internally, we have this golden rule: we're only going to use AI to benefit our learners. Some people may imagine that, you know, some companies may be firing people and having AI do their job. That's not what we're doing whatsoever. Our team has gotten significantly better at using AI over the last couple of years. And that has allowed us to do a lot more. It has allowed us to put out a lot more content, a lot more learning content, etc. We as a management team are not necessarily tracking like, oh, are you doing something that AI can do or not. We're just really trying to tell everyone try to be as efficient as possible with AI and our employees are doing that.
And can you give me some of the best examples from the team for someone who's watching this and they're like, okay, my manager tells me to start using AI but I have no idea how to do it. Do you have like best case examples?
It depends on what your job role is. I think most of our engineers have basically really changed their workflows. They're using AI coding tools. A lot of our product managers, what they've decided to do is using AI to make prototypes of things. So the product manager may not be implementing the thing in the full production app, but rather than coming to us with a written document, they come with a prototype. Now that's way better because it allows for much better decision-making. So, if somebody comes to me with a written proposal and says, you know, I'm going to do a way to teach Spanish better, it's hard for me to know what that actually means. But if they just show me the prototype and I can see that it really does seem to teach Spanish better, it's much easier to give approval to that type of thing. So, it depends a lot on the role.
Do you give them any guidance like, okay, instead of doing this, do that next time or how do they even find out they can do these things with AI?
We try to do some things in the whole company to try to, you know, we had for example a few months ago we had a day where everybody in the company had to vibe code something, not just engineers, every single person, people from HR, people from the finance team, everybody had to vibe code something so everybody could see the power of it. We also have a lot of documentation about best practices but generally people here in Duolingo are pretty smart. They're always finding new things and I think what happens is rather than management telling them what to do, they tell each other what to do. We have a lot of Slack channels that, you know, one of them is called Best AI Practices and so people are just saying stuff. We also have another one that's called AI Fails which is all the times, all the things that people... it's an incredible thing, very empowering for people who are like, oh my god, I made, you know, usually they're very small apps but it's like, I made an app. One of the things that has happened inside this company is everybody has made their own dashboard for their KPIs or something.
Yeah. For whatever it is, whatever it is they're tracking.
I mean, I see a few product managers that have vibe coded a whole thing with like our users in every country and what they're doing.
That's super impressive. And is that how you track AI proficiency? Because now it's part of performance reviews, right? At Duolingo,
For a while it was part of performance reviews. We decided not to do that. And I'll tell you why. I sent a memo to the company that said, you know, part of your performance review is going to be usage of AI and we found that people were, I don't know if they were doing that but they were kind of asking like, do you just want us to use AI for AI's sake? And at the end we backtracked and we said no, look, the most important thing in your performance is that you are doing, you know, whatever your job is as well as possible. A lot of times AI can help you with that but if it can't, I'm not going to force you to do that. So I think we backtracked from that because it really felt like rather than being held accountable for the actual outcome, we're trying to just push something that in some cases did not fit.
And do you have a specific example where somebody did something in a week without AI and then with AI they kind of multiplied the output?
We now teach chess on Duolingo. So you know, for a long time we only taught languages, now we teach a few other things. Chess is the latest course we added. This course got started by two people, neither of whom knew chess, neither of whom knew how to program. They basically vibe coded the first prototype of it. Now the final version that is actually in the app, of course we put some engineers in there, etc. But they really got very far in a span of about 6 months. They created the whole curriculum for chess. They created a prototype of the app entirely with AI. And again, these people did not know any chess.
And whose idea was that? Was it their idea to
It was their idea to do that. They also, it was well, they're the ones who wanted to add chess. By the way, they came to me a year earlier to say, 'We want to add chess.' I said, 'I don't want to add chess.' Because it's just a game and we're an education app. But what happened was that a few months later, I talked to the minister of education of my country. I'm from Guatemala. And she said to me, 'Our education system, our public education system in Guatemala is so broken that I'm considering sending every student a chessboard so that at least they'll learn logical thinking.' And when she said that to me, I thought, 'Oh, wow. Okay, this is actually part of education.' So then, this is when I told them, 'Okay, you can add the chess course.' But I said to them, 'But I don't have any engineers to give you, so go ahead.' And they figured it out.
And now it's your fastest growing course.
Yeah. It's, I mean, at this point we have seven million daily active users that are learning chess.
Wow, this is fascinating. Can you tell me step by step what was their process? So if somebody's watching and they're like, wow, if Duolingo is able to do such a spin-off which is kind of different from languages. If I want to start something with AI and build a fast growing product, what are the like five steps they need to take?
These two guys, the first thing they did was probably learn chess, probably because they didn't know any chess and that's one of the reasons they wanted to add it because they themselves wanted to learn chess. But after that, what they did is they really started looking at, you know, kind of the different tools that are out there for learning chess. They were basically doing market research trying to figure out what's out there for learning chess. They found that really what was out there was not all that great. And then they decided to start vibe coding something. To be fair, this person does have some technical knowledge. They're not an engineer, but they have some technical knowledge. And so they downloaded Cursor and at first they made just chess puzzles. Then they realized that the AI was not very good at making chess puzzles. So then they decided to train it with some, there's an online database of a lot of different chess puzzles. So they trained the AI with that and it got a lot better. And then after that what they started doing was just more and more mobile prototypes for me to play with until I told them that it was kind of good enough to really put it in the app.
And then you put it in the app and then did you give it an external push or people just started discovering it?
By putting it in the app very quickly a lot of people came but chess really has a big draw. I mean we put other courses in the app that have not grown as much. For example, it turns out chess is more fun than math.
So someone, a student who just heard about your chess course that was spun out so quickly and they want to start building something with AI today. What advice would you give them?
Well, the biggest advice I can give them is to start. You know, a lot of people talk a lot about starting. They're like, 'Oh, I have an idea,' but the biggest thing is just sit down and do it. You will learn a lot by just trying to do it. So that's the biggest thing. Other than that, you know, try to learn how do some of the best tools work. Certainly, vibe coding will help you a lot, but it's not just vibe coding. I mean, trying to make, you know, the initial designs for it. Now, you can have AI tools to make the initial screens and everything. So, use it all and try to make the thing. I mean, I haven't quite yet seen somebody who knows nothing about programming to really make a good app, but I have seen people who know a little bit about programming make apps. So, I would tell you it's still worthwhile learning kind of the structure of programs. That seems important. So, even though you may not actually need to program like word by word, just knowing how things work. For example, knowing the difference between the server and the client, like just these very basic things. I think that's important.
Did it give you more ideas to add more courses that are non-language related?
Yeah, it's given us a lot of ideas. We are not yet working on other stuff, but we have a long list of things that we want to teach, all kinds of things, K through 12 science, we want to teach, again, we're not yet working on that. We want to teach K through 12 science. We want to teach how to draw. There's all kinds of things, but at the moment, we're not really working on them because we want to continue working on chess, math, music, and languages.
Got it. But then any employee can just go and vibe code one of these courses and show you and maybe
Yeah, that's what I tell the company by the way. A lot of times people come to me and they're like, what course are you going to add next? And I, you know, one of the things I tell them is I wanted to add K through 12 science and then we added math. I wanted to add K through 12 science and then we added music. I wanted to add K through 12 science and then we added chess. At this point I also want to add K through 12 science. But it turns out that what people do here is somebody comes up with a really good idea and if it's good and they're passionate about it, we let them do it.
Yeah, they do it. Let's go back to actually the AI failure chat. Can you recall any examples of AI actually failing in a task?
Oh, yeah. I mean, there's a lot of things where it's failing. I'll tell you the biggest one which I think we're starting to see a difference here, but it wasn't the case a year ago. If you were to look at Twitter and just read what people are saying on Twitter. Two years ago I should have fired all our engineers because on Twitter they're like AI is better at coding than engineers. This is kind of for the last two years this is what they've been saying on Twitter and it was an interesting thing because I would come here and I would not really see a speed up on engineering. And I'm like, well, what's the disconnect, why? You know, there's all these people saying that AI is better at coding than humans. And the reality is it's not yet the case that AI is better at coding than humans. I think you still really need engineers and you're going to need them for a long time, I think. But we've just seen a lot of cases where you tell the AI to program something and sometimes it works, but the other, I don't know what fraction of time it doesn't work, but when it doesn't work, there's a real problem in that because you don't really know what it did, it's really hard to debug it. And that's kind of what has happened that you get into the happy path is really fast. Okay, it worked. But the unhappy path makes it so that it takes so long that you end up spending more effort on that than the time you saved on the other things. So we've seen that quite a bit. We've also seen AI not be able to generate things like narrative, like stories. Sometimes it does a good job, sometimes it doesn't do a great job and it just comes up with things that don't make any sense. You know, it's interesting because when you see a demo and you ask it to come up with a story, somehow those demos always look amazing. But then when you try to come up with a hundred stories, you realize that only like 30 are good and the other 70 are not.
So human still needs to check and select.
Oh, check. Yeah. All our content needs to be there. There's a lot of steps to try to either check it or spot check it or something to make sure that the quality is high.
So if we compare today and a year ago, how much more productive the company is with AI?
I don't know. It's more in pockets. And I don't know if any larger company that has seen like a 10x speed up in like... I don't think so. I think startups really see it because when you're a one person team then you work... one person can do a lot of stuff. With a larger company it's harder. It just turns out for example most engineers don't spend eight hours a day coding. They have to go to meetings. So there's a part of it that you just cannot speed up. Then there's the part that they spend coding. Okay maybe you can speed that up but you cannot speed it up, at least at the moment you cannot speed it up by a thousand x. I don't know. We're seeing some speed ups here and there in different pockets of the company. But again, it's what you said. One person companies are a lot faster, but it's because you don't have to interface with all the other parts of the company, etc. Also, AI is not as good with existing code bases rather than with a brand new codebase.
We've been talking a lot about how AI is changing the way people learn and retain information. And that got me thinking about something I changed in how I organize my own daily life and work. Someone told me once, if you're not capturing everything that happens in your calls with your team, you're actually losing to other companies. You're losing decisions that were made. You're losing context that gets dropped, things you're committed to, and then you just forgot. Team syncs, strategy sessions, call with investors, even a quick conversation with a contractor. It all disappears the moment the call ends. And I don't know about you, but I'm on calls every single day. Sometimes I forget to press record. Sometimes I don't think the conversation is worth recording, but then after the conversation, I realize I had to actually record that. One of my friends told me, 'Marina, you should start using Granola. You'll be blown away.' And now I use it on every single call. Now, it is an AI notepad for meetings, but it's not a bot that joins your Zoom and makes everyone uncomfortable. It transcribes your computer's audio in the background while you stay completely present in the conversation. It listens to every call automatically. And if it's a recurring call, merges them by folders. So, by the time the meeting ends, you have clean, structured notes ready to go. And after the call, I chat with my notes. I'm like, 'Okay, we just had this conversation. Can you create a follow-up email that I'm going to send to Monica, my manager. We're going to proceed with this, this, and that.' Creates the email and I just send it. Takes 15 seconds. It works across Zoom, Google Meet, and Teams. It's one of those tools I genuinely can't work without anymore. And I don't think you'll be able to either once you try it, try it on your very first meeting after this episode. Head to granola.ai/marina to get three months of Granola for free or enter the code marina at checkout. I left a link in the description. And now back to my conversation with Luis. What about you as a founder? Does AI help you make decisions or any workflows that work for you?
Research? Sure. It used to be the case that whenever I had something that needed to be researched, like I don't know what is the chess landscape in India, for example. You know, it used to be the case that I needed to either spend a lot of time myself or get a team of people to help me. Whereas now I can get a pretty good idea by just asking Gemini or something like that. So research I do a lot more by myself. That has helped me but ultimately the decisions are made by me. It's not like I asked the computer what would you decide? Okay. I haven't.
So you don't use it as a coach or you haven't vibe coded your own KPIs or whatever.
I've done a bunch of vibe coding for things but yeah certainly my KPIs but it's not... decisions I still make myself.
Okay. Yeah. Okay. I interview a lot of cool people on this podcast. In the past three weeks, I had Reid Hoffman and Bill Gurley who are legendary investors and I asked them a question. What is the first market that's going to be completely changed by AI and market you should be looking at? And they told me language.
Thank you so much. You know, it's been my thing for 10 years. What do you think?
I don't know what that means, change. So,
Like you don't have to learn a language because everything is translated?
Oh, no. I just don't buy that.
If you look at our users, we have more than 100 million active users. Half of them are learning as a hobby. It's a hobby. Whether AI can do it or not, it's a hobby. Actually, chess is a great example. You know, computers have been better at chess than humans since 1997. A lot more people are learning chess today than they were in 1997. It's a hobby. So for half of our learners, it's a hobby. And I don't think whether computers can do it or not, I don't think it'll matter. The other half are learning English. And I think anybody who tells you that people don't want to learn a language has not had to learn English.
It's interesting how you say like 50% they're probably learning other languages. Hobby. Yes. English necessity.
Yes. But that's how it is in the world. Like if you're learning, I'm sure there are, I'm generalizing here, but generally if you're learning French, it's a hobby. It's not always true. I'm sure there are people who actually need to move to France, but it's a small fraction. The majority of people in the world that are learning French, you know, want to feel cool when they go to Paris so they can order a croissant. And that's our users. And again, somebody who's lived their entire life in the US, has never had to learn English because that's their native language, etc., will say something like, well, languages are unnecessary, etc. But somebody who's had to learn English, it's a different thing. It's just you just need to learn English. And you may want to move to an English speaking country. You may need to do an educational, like you may need to go to a university. Nobody's going to be allowing you to go to a university with like a phone that translates everything the professor says. Like that's just not... So I'm just not particularly worried about that.
Is there a fraction of the market? So I'm thinking about translators for example. Somebody spends like four years learning that. What would you say to those people?
Depends on what it is. But there are fractions of the market that are probably going to change quite a bit. Also, in terms of the demand, I agree that some people may have wanted to learn a little bit of a language if they were going to, you know, just visit Germany for 2 days that maybe now they're just not going to do that because they can just... but at least when you look at Duolingo's users, that's a very small minority of our users. The majority really are hobby or English. So I'm just not worried. The other thing about language translation is that simultaneous language translation has been really good for... this is not an LLM thing, like LLMs are good at it too but Google Translate did not use LLMs and it was really good 10 years ago. So I just, you know, we've seen the demand to learn a language actually go up as opposed to go down so this is not something that we internally are worried about. But I understand people say that.
Yeah, I'm also thinking like if you have glasses for example that are smart and they translate everything for you automatically. I haven't seen the case with the headphones. I don't think people really use the AirPods to translate. No. Then I'm thinking maybe it's glasses that translate the signs. I don't know. It's because when we came to Silicon Valley, I think 2015, we were pitching our company LinguaTrip that does like language travel, language courses. And I think 50%, but to your note, American investors were like, 'Oh, this is not a market. Oh, this is going to go down.'
We've had this problem at the entirety of the company of Duolingo. We are a company based in the United States. You know, when we first pitched Duolingo to investors here, you know, however many years ago, the most common thing is like, nobody really wants to learn a language, math though, people want to learn math. And that's, you know, I'm sure investors think that because they are good at math and they wanted to learn math but the reality is there are more people learning languages in the world than there are people learning math.
What was your mindset when the smartest people in the world tell you that? You're like, I don't care, I just
I mean, I, you know, I grew up in Guatemala. I could see what it was to have to learn English. Look, it is a huge thing to learn English. It changes people's lives.
I know, that's my case as well.
It changes people's lives.
Do you have another worry that, so, you have an app, right? But now we're in the era when anyone can vibe code an app for themselves. What if I go to like, I'm learning English, I go to Claude and ask, can you gamify my experience, create me an app that's personalized to me, you know, my interests, you know, my hobbies. Do you worry about that?
A little bit, but not really. I mean, this, it's funny, inside the company we never talk about this. This is, you know, we see again, we see Twitter talking about that or investors talking about that but we internally don't talk about that. Look, ultimately I think you can ask AI to make you an app but making a really good app is not that easy. You know, ultimately we for example have data from hundreds of millions of people about how they learn a language every single day. More than a billion exercises are answered on Duolingo and we use that data to teach you better and so we just have a lot of data on how to keep you motivated. You know, there's probably two, three thousand language learning apps in the world. They've been there and now with vibe coding now there will be probably 20,000 rather than two, three thousand but at the moment we're just not particularly concerned. You know, something may happen.
Is there anything concerned? Because I'm asking a question about it because I talked to people and they're like, this is going to be eliminated. This is going to be, we're done. And you're like, it's fine.
No, I don't, I wouldn't say that it's like all is fine. I do think a lot of things are going to change.
What do you think is going to change? What are you preparing for?
I think that user expectations are going to change and I think we have to stay ahead of it. So, a good example is, you know, one of the things we have in the app is conversation practice with AI. When we first put that out there, the cost of it was high for us. So, we put it behind the most expensive tier. So that so you have to pay a lot of subscription to get the conversation practice. At the moment the cost of that has come down enough that we're going to start giving it to much cheaper tiers and we are probably going to eventually give it away for free.
We're doing that because I believe that customers are going to start expecting that. I think there will be apps that start doing this for free, and if we don't do it now, we'll be forced to do it in a few years. So that's the type of stuff we're doing to prepare for this because I think we just need to stay ahead.
Yeah. So users will expect more from...
I think users will expect more. I think users will expect the apps to be a lot more intelligent, which they should.
We're undergoing kind of a platform shift here, and what ends up happening in platform shifts is that the companies who were the winner before the platform shift may or may not remain the winner after that. So I hope that we can do that.
Also talking about AI and workforce. I just talked to Gary Vaynerchuk, and I really like what he said. There are a lot of rumors of large companies firing people and they say it's AI. Then Gary said something that struck me because he said if I fire 100 people, my competitor hires them and they still 10x their output, like I'm dumb for firing them. How do you think about that?
We have never laid anybody off here. We have never done a layoff, despite what the internet may think.
We've never done a layoff here. I think that it is important to continue hiring people because now the way I see it is a single employee is just way more productive now than they used to be. So I get better return on investment by having another employee. That's how I see it. I mean, I of course cannot speak about the very specific companies, but my sense is that at least in some of the cases AI is just an easy...
Yeah. I mean usually what happened is you overhired, and when you overhired, you're like, okay, because of AI we're going to do that.
I don't, at least at Duolingo, the way we run the company...
I am surprised that there are companies doing that because I see no reason.
Yeah. I was just at Davos and I was talking to somebody who releases their jobs report. All the layoffs are structural, like overhired during COVID. So it's not really...
A lot of companies overhired during COVID, and I understand that. And then if you overhired, you probably don't need these people, but blaming AI is an easy scapegoat.
It is. What he just said actually worries me the most. Everyone's talking about AI replacing jobs and big companies firing people. This is not what's happening here, right? He's actually hiring people, but he's hiring those who know AI. Same for me, we're just hiring a social media manager. And the questions I was asking them during the interview: how are you going to automate this? How are you going to use AI in this process? Founders are looking for people who utilize AI in their work. And this is actually what my newsletter is about. It's called Future Proof. And every week I share what we learned with AI. Like my PR person just Vipoded the whole website with all the transcripts from this podcast. And we share things like that in the newsletter. So first of all, subscribe to this channel and second, subscribe to the newsletter.
Can we talk about the stock price? Because when I was preparing for this, I saw the 82% collapse of the stock. But what I really want to talk about, because you explained that to your shareholders, can you walk me through your mindset as a founder when you make such decisions who make your users happy but they don't make your investors happy?
Well, the decision was made by AI. Oh, I'm kidding. That is a joke. That is not what happened. I made that decision. Look, we made a conscious shift in how we run the company. I made a conscious shift, and certainly the executive team was behind me. But we got to a point where, if you look at over the last five years, we've grown a lot. We became a public company in 2021. We have grown our active users by more than 5x since then. So we've grown a lot. We've also grown our revenue by a similar amount, etc. We've grown a lot, but two things happened. One is that throughout 2025, we've been still growing, but we were growing slower than we were growing in previous years. So that's one thing that happened, our user base was growing slower than in previous years. The second thing that happened is because of AI, I really do believe that education is going to change quite a bit. And we are a really important player in the education category, and I want to be in a situation where we can lead some of that change through AI. So the combination of I want to lead through that change in AI and our user growth slowing down told me we need to do something important, change how we operate so that we continue grabbing as many users as possible. Now that comes with a cost, which is we are not going to be monetizing our user base as much as we were before, and investors don't love that.
When we made this decision, we talked to, of course, all internally, our finance team, everybody agreed this is going to decrease our stock price.
Did you expect that number, like 80, 82%?
I didn't know exactly what to expect, honestly, but I knew that it was going to be a lot. So we knew that, but we made the decision consciously because we think that if we continued operating the way we were operating, we probably could have continued growing a little bit, etc., but at some point it was going to be capped. Whereas, I think if we really try to get a much larger user base, we're going to be a much larger company in the long term. And the thing is, I'm operating this company. I mean, I'm hoping that this is my last job and this is the last thing that I do. And I have many more years of energy left.
And you never regretted the decision?
That is amazing because as a founder, hearing from the market what they think about your decision is tough.
I know. I agree. Look, it's not that it hasn't been tough. I don't regret the decision because I believe that it is the right decision, but it's, you know, yeah, it's been tough. I really still am very convinced this is the right decision.
Do you feel like, because you're founder of a publicly traded company, does your mood depend on your stock price?
It used to when we first went public. It used to. I learned to stop looking at least every day. I mean, it's not that I don't know the ballpark, but I don't look every day. It used to be the case the first year or so. It'd be like it went up by a dollar, it went down by a dollar. Now...
Like you're used to it because as a creator, my self-worth depends on how my last video is performing, which is not right, which is not good for my mental health. I'm learning how to not look at it.
Well, I will tell you this, the same is true for me, but not with our stock price. It's with daily active users.
So you still have the same...
I just moved it to daily active users. So every morning, yes, it's growing and everything, but every morning, our daily active user report for the previous day comes at 5:00 a.m. Exactly. I wake up very early. Every morning at 5:01 a.m., my mood gets set.
