. Hello, everybody. Thank you for coming. My name is Hassan. I'm super excited to be here today to talk to you about how to use open source models to build AI apps with millions of users. I've been building AI apps for several years now, and I just want to come tell you a little bit about my journey, show off some of the apps, and then tell you about kind of my whole process of building these apps from idea to having the finished app, and how I market them as well, and then some advice overall.

So I'll start off with some intros about who I am, Together AI, the company I work for, why it's one of the best times to build right now, and then we'll get into demos. I'll talk about my tech stack and architecture, and then I'll end with my process for building these apps, the advice I have for other people building these apps.

So I lead developer relations for an AI and for a company called Together AI, but probably the most relevant part for this talk is the fact that I build a lot of these AI apps, and I've probably averaged one a month for the last four years, and I've been fortunate enough that some of them have done pretty well and have gotten a good amount of users and GitHub stars as well.

One thing I do also is open source, so I'm going to show off some demos, but also you can check those out in your own time and you can dig into the code as well. Like I said, I lead developer relations for an AI cloud platform called Together AI.

We're a platform for open source models. We give you an inference API to be able to query really any open source models probably that are out there that are good. So we have chat models like QEN3. We have reasoning models like DeepSeq R1. We have image models like the flux context model that came out recently.

We have vision models, audio models, you know, almost all modalities. We also let you run these models on dedicated instances or fine tune them on your own data. And we have a GPU cluster product as well if you want a training cluster. So before I get into the demos, I just want to talk about the fact that it's really a historic time right now for building.

And I think this is because of two things. Like one, I think the barrier for building has lowered dramatically with a lot of these AI tools, right? You can use Cursor and Windsurf with your IDE to auto-complete stuff. You could use these AI builders like Bolt and V0 and Lovable to prototype apps really quickly.

You can use chat apps to kind of brainstorm ideas or go through the process of building an app. You know, you can go to a chat app and say, "I'm building a Swift app for the first time. Can you guide me through how to do it?" Right? So I think like the the barrier has lowered on one side and on the other side we're having these like groundbreaking models come out every single week that are enabling completely, enabling builders to build completely new things.

So it's like these incredible AI models are coming out that you can build with and it's gotten a little bit easier. So I just think it's an incredible time to be building apps right now. I'm going to dig into a couple of demos. These are some of the apps I've built that I'll spend like 30 seconds on each one demoing really quickly.

But one thing to note really quick is the fact that some of these apps have a couple thousand people that have used them and then some of them have like a million plus. And I think like at a certain point it is a numbers game and you kind of have to try out a lot of different stuff.

And I'll talk about kind of how I approach that. So we'll switch into some demos. So in the beginning when I was when I started a building kind of a few years ago, I wouldn't know what to build. So I'd go on Twitter and I'd look up, you know, people that tweeted like, "Oh, I need an app to do this." And so here Samina said, "Can someone build an AI app to help me pick some glasses?" And I was like, "Sure, I got you." And, you know, built this little tool that takes a bunch of different requirements, turns them into a query and then actually uses the Amazon API to find products that you can actually, you know, click on and buy.

And another one of these was one of my friends Theo tweeted out like, "You know, I just want an AI app that writes my commit messages for me." And my CTO at the time was like, "I love that idea." And so I just decided to build it. And all it does is when you do git add, it takes the git diff, it sends it to an AI model, and it writes a commit message for you, and it kind of shows it to you and you can kind of accept it.

So this is one of my first apps that I built that ended up doing really well and got, I think I got about 40,000 people that have installed it and downloaded it. And it's also open source. And I had a bunch of people contribute, which has been great. Another app I built was a like text-to-app builder.

There's a bunch of these where you can type in an app that you want to build. Here I'm going to say like a quiz app about American history. And the way this works is it takes this prompt, it sends it to an AI model to come up with a project plan, and then it sends it to another model to actually write React code that we can show.

So in a second this should populate, but obviously also open source. I've had about 5 million requests go through this app and about a million apps built just through this. And I have a little over a million people that have ended up using it. So this is an app that kind of just generates images as you go through it.

And also has about over a million people and has about 48 million images that were actually generated with this app. I have an app called napkins where it takes a screenshot of, the idea is it takes a screenshot of a napkin. The idea is like you draw a little web app on a napkin, it takes a screenshot of it and it can actually build it for you.

So yeah, that's, that's another one of my apps. That one has about 40,000 users. I have another one that lets people kind of upload a resume and then builds them like a personal site like this for people to check out. And you know, there's, there's a bunch of others, ones that visualize menus.

I built like an AI chat app, like a tutor app where you can, you know, put in a topic that you're interested in, like personal finance, and it can explain it in the level of like an elementary school, a person, and then some OCR stuff as well. So I'll get back to the slides.

A lot of these apps have a very similar architecture that I end up using. And so this similar architecture starts with a user coming in and typing something or uploading an image usually. So it's some sort of user input, right? And I take that and I generally will send it to an AI model on Together AI.

So it could be like an image to image app where I take an image and I send it to an AI model to make another image and then show that to the user. So step two is I send it to an AI model. Step three, a lot of the time is I store that image or that text in the database to be able to show it to the user.

And then step four is I just show it to the user. So it's a very, very simple architecture. A lot of the time, there's one single API call happening. The user does something, I send one API call to an AI model, I get the response back and I show it to the user.

And I think it's this simplicity that is really, really important, both for moving very quickly, but also for validating these ideas. The more simple you can drill down an idea, the faster you can kind of build. And then this is my tech stack that I usually use. I use Together AI for all of my AI models.

I use Next.js and TypeScript as my full stack framework for building things. I use Neon as my database. It's like a really good serverless Postgres host. I use Clark for authentication. I use Prisma as a way to talk to my database and TypeScript. I use Shatzian and Tailwind for styling.

S3 for uploading images. Plausible for website analytics. And I kind of showed you guys this in a couple different places. So it's cool that I can see the number of unique visitors. I can also see where they're coming from and what countries and what device they're using it on.

And one thing I always get very surprised by is the fact that a lot of people use most of my apps on mobile. So it just goes to show that the mobile experience is really, really important. So plausible for website analytics. Helicone for LLM analytics so I can dig into my LLM requests and like troubleshoot things.

And then Vercel for hosting these apps. Cool. So I'm going to talk about my process for building these apps. And a question I get a lot is like, how do you come up with these ideas? Uh, and, and I think like the, the biggest thing I did for ideas that, that helped me out was just to keep a list of running ideas.

Um, I think we all get great ideas at random times and most of us don't write them down. And I think like, uh, that makes a lot of the difference. And so I think keeping this list of ideas, uh, trying to write down anytime you see an interesting idea or see an interesting product and you say, oh wow, that's actually really cool.

Maybe I can use a similar methodology to and apply it to something else. Um, so ideation is like, uh, a big thing. And, uh, the list of ideas I have, I usually always have this short list of like the top five. And so I like, I know right now kind of the top five apps I want to build next.

Um, and then if anything kind of drops in between, then I'll, I'll build it. You know, if a new image model comes out next week, that's like really, really incredible and open source. Um, I'm probably going to be scrambling to build an app with, with that. Uh, naming is another big one.

You know, you want a short memorable name. I, you know, you can use AI tools like domains GPT to kind of, uh, check names that also have the domain name available, uh, to, to use them. Uh, number three is design, you know, thinking through how the app will work.

Like, you know, I'm going to have a landing page and a user is going to click like enter and then enter and get this page where they upload something and then they see an image, you know? And so it's like these two screens and, uh, you can either kind of sketch it out on a piece of paper or you can use Figma, uh, or you can use a lot of these prototyping tools, uh, to, to try to help you think through, uh, what, what the app is.

Uh, and then I go about building the actual app. So trying to make the simplest possible working version of a specific app. Um, and like I said, I, I always try to shoot for like one API endpoint, you know, like one, like just very, very simple. Um, step five is like, you know, I have a working prototype now.

I, I start to think through, uh, authentication and limits of like, okay, like how expensive, uh, is this? Like how many, um, how many uses uses do I want to give each person per day? Do I want to want to add authentication? Do I want to add, bring your own API key?

Uh, so it really just depends on, on the app and the AI model that I'm using. Uh, and then step six is usually kind of prepping for the launch, getting a nice OG image, getting a domain, adding analytics, uh, writing a nice read me. Cause like I said, everything I kind of do is open source.

So I also want to make sure the code is really easy to use and really easy to, uh, to clone. Um, and then the last step is actually launching. And so I usually use LinkedIn or X to, to launch and, uh, you know, kind of, uh, just see what people say at that point.

Cool. Final section. Uh, and then I think we'll get into some Q and A. We have a little bit more time because the demos didn't work. Um, so advice for building apps. I have these like seven tips that I'm going to go through. Uh, one is thinking of an idea that excites you, but is very, very simple, uh, that you should be able to describe to anyone in five words, right?

Like blink shot, generate real time images, llama coder, go from some text to an app, right? Like, and I think this is one of the biggest mistakes people use as they try to, they try to think like, okay, you know what? I like, I want to build this like personal CRM software that has this dashboard that will email me every week and do this and that.

And you know, they come up with this like grandiose version and spend like six months building it. And then they realize, oh wow, it's like, it's, it's, um, this isn't, this wasn't the right thing to build or, um, this is just like really hard and nobody cares about it now.

And so it's all about, uh, thinking of an idea that excites you, but it's also a really, really simple number two. And this is very underrated is making sure the UI looks good. A lot of the apps I showed you are AI apps, but I actually spend 80% of the time on the UI for most of my apps.

Um, and that should tell you like how, how important this thing is. I, I've like the first few apps I've built kind of looks really, really bad. And that was a big part of why nobody kind of used them. And I've started learning that even if you take a really simple idea or something that's like so simple, like summarizing a PDF, right?

You can go to ChatGPT and summarize a PDF right now, but I built a PDF summary app and I spent a lot of time making it look really, really, really good. And then I had tens of thousands of people that ended up using it. Um, so it's all about making it look really good, making it really easy to use, and making it really, really straightforward.

Um, the third tip is just keeping the app simple. I talked about this a bunch, but most of my apps have only one or two API calls. Um, tip number four is trying to incorporate the latest AI models. A lot of these apps, um, that, that I showed you have like used some of the latest AI models like BlinkShot, the real-time image generation app, um, that used, uh, a model called FluxChannel.

And I, and I launched this app, I think two days after this model came out. Um, and so it was one of the first apps that leveraged kind of this new technology or this new, really, really fast model that was good. Um, and so doing that kind of increases, uh, the potential for, uh, virality.

Uh, tip five is launching early and then iterating. Um, for a lot of these apps, like still to this day, you know, like 40 apps later, I still have no idea what will do really, really well versus what won't. Um, and the only way to de-risk this is to simplify your project, to launch early.

And then if nobody really cares about it or not a lot of people use it, then at least, you know, you didn't spend six months building, you spent a week building and you can kind of move on to another idea. Cool. Uh, another tip that I, that I've kind of done is trying to make it free and open source.

Um, so folks can kind of learn from you and are also very incentivized to share it. Um, and so, uh, the, the, this is something that that's worked well, uh, for me. And then the last tip I have is, uh, just keep shipping. Um, a lot of AI apps, like I said, don't do very well.

It's a numbers game. You have to kind of keep building and building and building. And the more you build, the more you realize, you know, kind of what resonates and what doesn't, the faster you get at building, uh, and the better you get at like picking, picking ideas. So, um, a lot of it just comes down to, you know, putting in the hours, building a lot of stuff, and then, uh, seeing what happens.

And that's all I have. We actually have five minutes for Q and A if anybody has any questions. Um, and yeah, I think you can line up at these, uh, podiums and we can, uh, take a few questions, but just, uh, before that, uh, you can find me on Twitter at nutlope or, uh, my email hassan@together.ai.

Uh, we also have a Together AI booth here at S25. Um, I'll be there, uh, for a few hours after, after the talk. So, uh, come and talk to us. Yes. Yeah, I'll just yell. Uh, oh, it's on. Okay. Uh, thanks for sharing. This is great. I'm just curious.

Uh, you have a lot of traction success more than many, most YC startups. Why don't, why don't you just start a company? It seems like the perfect formula. I'm just really curious. Yeah. Um, that's a good question. I mean, a part of it is I, I really enjoy, um, I really enjoy teaching and a lot of these apps, like I can, a lot of these apps, first of all, do well because they're free and open source.

Right. And so, because I'm, I'm strictly not trying to monetize them. I'm, I'm strictly like trying to make them free and I get companies to kind of sponsor it and, and, uh, and, and keep it open source. Um, so I just kind of enjoy doing that and launching these apps.

And I, I will also like make videos and blog posts about different things. Uh, but yeah, maybe eventually I'll, I'll come out with an idea that I really, really love working on and, uh, and, and do that. But, um, for now it's just been really fun getting to build a lot of the stuff and experience.

If you ever do start a startup, let me know, uh, how Andrew invest. Thank you. Yes. So what are some common trends with ideas that maybe you thought were good, but didn't resonate with people and the reverse? What are the surprises been? Yeah, that's a really good question. Um, where have the surprises been?

It's, it's been a little bit random, honestly. Um, I think, I think one insight I got is like building apps where people can very easily share what they create tend to do way, way better. Um, and so now I try to think about that, like building in that viral loop into my apps on like, if you can generate an image, I want to make it really easy to share that image or and share it with like a really nice OG image.

Um, and so that's one insight I've had is like, you know, apps that have that viral loop of, of like, Oh, this is really cool. And I can share this with a friend and they can go on it and try it out and they can go on it. Um, and so that's something that I've incorporated a little bit more.

Yeah. Yes. I love that you're making all of this, like, you know, it's all free so far. It's not monetized, but how are you paying for like all the compute and the model calls yourself? Like, are you funding this? Yeah, great question. So, um, first off, you know, I, I work at together AI, we sponsor all of the compute in terms of the AI models, uh, but then I'll also partner with other AI companies like neon gives me a free database to use their database and, and like, you know, all like Clark gives me a free account for authentication.

And, uh, uh, and the reason for that is because it's, it's, it's all open source. So it's, it's in their best interest to be in that open source project and, and for people to use it. Um, and so that, that's also, uh, like a good piece of feedback I have for people is like, if you want to just tinker with apps and build them, a lot of people are like, oh, but I can't launch an app because AI models are too expensive or this thing's too expensive.

Um, more often than not, if you launch something and you reach out to these companies and you say, hey, like I'm building this, this open source app, can you please give me some credits? More often than not, they will. Uh, and so that's generally how I do it. Awesome.

Thank you. Yeah. Yes. Yeah. Um, I mean, thank you for this talk. It was, it was really great. Um, I just had a question because you talk about how frequently you build these apps, like every, every week you said for, for a decent amount of time. Um, and you also talked about, you know, using the latest and greatest in AI models with them changing so quick and with you having so many apps out there, do you ever struggle with like going back through and, and like changing the models that you've used for some of these apps and how do you deal with that?

Yeah, that's a great question. Um, I, I think like a really cool, um, a really cool thing is the fact that you can do that. You can just build an app with an AI model and then a better AI model comes out three months later and you can go.

And a lot of the time it's like a one line change of like, let me update this model and the app just gets way better or it just unlocks new things. Uh, and so that's something I do frequently where I'll, I'll go back and I'll like, even like relaunch an existing app with a new AI model or add a, a tiny feature to it.

Um, and so, um, yeah, I, I think that's kind of the superpower of like building with AI is the fact that you can just kind of replace these AI models. Thank you. Yeah. All right. Awesome. Thank you all so much for coming. I appreciate it.