How a self-taught developer built an app with his voice—while running a marathon

The challenge:

Building is now easier than ever, but still constrained to your desk

AI and vibe-coding tools have made building software more accessible, letting people describe intent and iterate conversationally instead of mastering syntax.

But one constraint hasn’t changed: creation still assumes a keyboard, a desk, and stillness.

After months of coding almost entirely by voice, self-taught developer Tijs Nieuboer began questioning that assumption. If thinking and building had already become conversational, why did input still require sitting down and typing?

That question didn’t start as a stunt. It led to a simple test:If building no longer needs a desk, should it still work in motion: under real, imperfect conditions?

The solution: using Flow to voice code on the run

A DIY setup, invented from scratch

Less than one percent of people have ever run a marathon. None had ever built a working app while running one.This meant that he had to invent his own custom setup to make it possible.

Seeing his laptop while running

To get a laptop screen in front of his eyes, he started testing different AR glasses, most of which bounced so much while running that the text became unreadable.

One pair literally shook with every step. Another washed out in sunlight. The glasses he planned to use broke right before race week, forcing a last-minute buy of a newer model with built-in stabilization. That last-second swap turned out to be a blessing in disguise, because that pair was the best one yet.

Controlling his laptop with one hand

For control, he needed something that he could use to operate his laptop while moving, but no good devices existed. So he had to come up with his own.

He then discovered a software called Enjoyable, which lets you connect a game controller to your laptop and map buttons however you like.

First, he tried a PlayStation controller he had lying around, until he realized it required two hands. Then, he realized he could try a Switch controller! Tiny, light, and fit in one hand.

Getting everything to work together

In practice, getting everything to talk to each other was chaos. Some test runs ended with cables popping loose, screens disconnecting, or the controller refusing to pair. He’d cycle between “this might actually work” and “why am I doing this to myself?” on a near-daily basis.

The final setup

By the time race day arrived, his setup looked something like this:

• A MacBook in a backpack, with cables snaking out the top

• AR glasses connected by a long wire, stabilized with a headband so they wouldn’t ricochet with every step

• A Switch controller acting as a cursor, zoom tool, and emergency fallback when voice commands got breathless

• Wispr Flow handling all voice input, even when he was panting into the wind


It wasn’t sleek. It wasn’t polished. But it worked just well enough to give Tijs hope that this stunt was possible.

Race day: 42 kilometers of code

At the starting line of the Amsterdam Marathon, Tijs looked visibly out of place. Within the first kilometer, he lost his laptop connection. He didn’t stop running. He opened his backpack mid-stride, reconnected cables, and kept going.

For a few kilometers, everything clicked. He spoke code into existence. Variables registered. Files updated. People stopped him to ask if he was working.

Then came the setbacks.

Fogged glasses. Shaky breath. Too many commands at once. He restarted the project twice before finally getting it to stabilize around kilometer 18.

Between coding and running, he was also directing a camera crew that kept missing meeting points.

By kilometer 26, only part of the app worked. But he kept going anyway.

By the finish line, he had done two things:

• Finished the marathon
• Built a working app, entirely by voice

The app that kept him moving, and what it proved

The result was Hypes, a voice-based companion designed to keep people accountable to their goals. Instead of tracking pace or playing music, Hypes listens, reflects, and talks back when motivation dips.

“It was exactly what I needed in that moment,” Tijs says. “A voice that keeps you moving.”

Tijs built Hypes to mirror what he was experiencing mid-race: committing to a goal, hitting moments of doubt, and needing something that pushed him forward: not with generic motivation, but with a voice that understood the objective.

During the marathon, he entered his goal into the app itself: finish the race while building it. Around kilometer 35, the voice loop responded in real time. That was the moment he knew the experiment had worked: something real had been built, entirely by voice, in motion.

The story quickly spread beyond the run. After finishing, Tijs was interviewed on national television in the Netherlands and the story spread like wildfire through social media.