This dev built an app...while running a marathon

In most ways, Tijs Nieuwboer is just your standard entrepreneur and builder from Amsterdam. Except for one thing: He’s a bit crazy.

That's a good thing. 

After a year of coding almost entirely by voice inside Cursor while using Wispr Flow to write and edit code, switch between files, and navigate projects hands-free, he had an idea: What if he built an app entirely by voice coding while running the Amsterdam Marathon? 

Less than one percent of people have ever run a marathon, and no one had ever built a working app while running one. How did he possibly do that? In our interview, Tijs discusses his setup, provides his list of go-to tools, and explains what exactly you can build from start to finish line.

Product Hunt: How did this idea come to you — when and why?

Tijs: Honestly, I’m really happy using Wispr Flow. They’re the reason I came up with this idea. At one point,  I was coding for like five days straight. Part of it was over a weekend, and I just thought, “You shouldn’t have to type during the weekend.” So I kept using voice input instead for almost 48 hours straight. I did sleep a bit, but still, by the end of that weekend, I thought, “Why do I even have a keyboard with all these buttons when I can just push the voice button?” That’s actually kind of crazy.

At the time, I was also doing a lot of pitching work using this storytelling framework by Andy Raskin about breaking conventions. I remember thinking, “Break the keyboard” would be such a cool idea. There should be a device that gives you just one button—a single input—and your cursor. Then you’d be fully mobile. You wouldn’t be stuck at a desk anymore.

Of course, that led to the next question: you still need a screen. And that screen is locked to your laptop. I’ve always been super interested in tech and innovation, so I started looking for glasses that could simply mirror my laptop screen. I didn’t need a full smart OS or fancy features. I just needed glasses that could connect to my laptop screen so I could control it on the go.

Then I found a pair online. And suddenly I realized I could actually do anything. And without thinking too much, I thought, “Wait, I could even run a marathon!” I got so excited by the idea. I’d never run a full marathon before, but I had done some half marathons and was decently fit. So I figured I could train. This was around June or July, so I had about four months to prepare.

I started sharing the idea with friends to create a bit of peer pressure to make sure I’d actually do it. And that’s how it started.

Product Hunt: What did you choose to design while you were running the marathon?

Tijs: The app I built is called Hypes, and it’s essentially a virtual hype man. I thought about it a lot and wanted it to fit the story of running the marathon while building something at the same time. I wasn’t sure if I’d be able to finish the marathon. When you train for one, you usually only train up to about 30 kilometers.

So I thought, “Okay, if I don’t make it, I’ll need someone to hype me up.”

That idea applies to a lot of goals and challenges. At one point, I even thought about bringing a little speaker so other people could get hyped too.

The app itself is simple: you open it, enter your goal. In my case, it was “finish a marathon and build an app.” Then you join a room where the hype man responds to you. The hype man acts kind of like ChatGPT with a voice, but with a different personality and instructions. It hypes you up, reminds you why you’re doing what you’re doing, and keeps you focused. It’s a little silly and over-the-top, but that’s what makes it work.

Product Hunt: So what was the process like while you were actually running? You had your phone in one hand?

Tijs: Let me explain, because there was more gear involved.

There are some great devices that let you control your laptop screen from a distance, but most of what I found was either cheap drop-shipping quality from Alibaba or really outdated. The technology existed, but it never found much of a market.

Right now, I think we’re entering a stage where people will work less from desks, so the timing is right for new devices like this. But because I couldn’t find the right device immediately, I downloaded this software called Enjoyable, which lets you connect any game controller to your laptop and map buttons however you like.

I had my PlayStation controller lying around, so I tried that first. But of course, you need both hands. That’s when I realized the Switch controller would be perfect! It fits in one hand. That’s how I ended up using that.

Before the marathon, I went through a lot of trial and error. We’d try something, fail, and go back to the drawing board. Eventually, we got the Switch controller working.

The hardest part was the glasses. They kept bouncing while I ran, which made it almost impossible to read the screen. You have to imagine how frustrating that is. Just before the marathon, I bought a newer version of the glasses. That was a game-changer because they had a built-in camera that stabilized the display. So even when your head moves, the screen stays still.

I was constantly zooming in and out to read the app I was building and see what the cursor was saying back to me. Then, right before the marathon, the old pair broke, so I had to buy new ones again, which ended up being a blessing in disguise.

Product Hunt: So you had three devices: your laptop, your glasses, and your Switch controller. How did they all connect? It’s not Bluetooth, right?

Tijs: Right, it was all wired. I carried my laptop in a backpack. It looked kind of funny. I even wore a headband to keep the glasses from bouncing too much. Then I ran a cable from the glasses to the backpack, and the Switch controller connected wirelessly to the laptop. It was very DIY, like a homemade cyborg setup.

Product Hunt: How did people react? Were they curious about what you were doing?

Tijs: Definitely. Some people didn’t notice, but others were really intrigued. I was basically talking out loud while walking, which made me look like I was in another world.

My buddy was walking with me, and he said everyone was staring, especially near the end of the marathon. We were pacing ourselves to finish in about five hours, and I was also trying to build the app at the same time. Whenever I walked too fast, he’d tell me to slow down.

Sometimes the connection dropped because of all the cables, so we had to pull out the laptop mid-race to fix it. People would ask, “What are you doing?” and I’d say something like, “We couldn’t take time off work, but we also wanted to run the marathon!”

It definitely got people’s attention.

Product Hunt: Were you ever actually running? Did you get out of breath? How did that affect the voice input?

Tijs: Oh yeah, that was a challenge. Wispr Flow is an amazing voice tool, but if you’re out of breath and there’s wind (and it really gets windy in Amsterdam), it’s not ideal.

At the start, I had trouble setting up the app. We had to reconnect everything a couple of times while running. You can’t really stop in the middle of a marathon. I think I had to restart two or three times before everything worked smoothly.

The hardest moments were when I needed to dictate short, specific words like “localhost.” Those are tough to get right through voice when you’re panting and moving.

Product Hunt: Since you were using only voice, how did you handle those kinds of issues?

Tijs: I used the accessibility tools built into my laptop. Funny enough, I didn’t think of that until around the 20-kilometer mark. I could use the mouse (which I controlled through the Switch controller) to type in words manually.

Before that, I’d literally say to ChatGPT, “Give me just this one word,” and then copy and paste it into the app. It wasn’t the most efficient workflow, but it worked.

Product Hunt: Did you end up using the app during the marathon, especially at the end, to get across the finish line?

Tijs: I did! We kept a slow, steady pace, so the marathon was manageable. Toward the end, I actually sped up a bit and chatted with the app, kind of sharing that end-of-race euphoria with it. It was a great moment.

Product Hunt: Do you see yourself doing this again? Maybe turning it into some kind of extreme sport?

Tijs: (Laughs) Maybe! I hope so. We already organize hackathons, and we’ve talked about doing something like a productivity run. There are so many running clubs in Amsterdam. It’s becoming a huge thing. We thought, how fun would it be to have a club where everyone runs and builds stuff at the same time?

So yeah, I’d love to do it again. It was definitely a stunt, but I’m open to doing more of them. I’m even considering running an ultramarathon next year and maybe selling the product too.

Product Hunt: Is your Hypes app ready to launch on Product Hunt?

Tijs: We’ve built the MVP and finished the basics, but we still want to improve it. We’re planning to launch it on Product Hunt once it’s polished.

The idea is to make it a real hype man for multiple goals, not just a voice analysis tool that gives boring feedback. We’re also talking to a Dutch influencer who’s kind of the ultimate “hype man” here, to see if we can collaborate.

Product Hunt: Some people might say, “You don’t need to be productive all the time.” What was fun about this for you?

Tijs: For me, the most meaningful part was the journey. I’m a big dreamer. I usually work toward long-term goals, but this was something specific and immediate: run a marathon and build something at the same time.

Preparing for it gave me focus. I met a lot of new people, learned a ton, and had to keep iterating. That process, the repetition, the problem-solving. That’s what made it fun. It was all about the journey.

Check out the video of Tijs in action.