San Fransico

Good Morning

I set my alarm for 9am… and of course I slept right through it. Woke up late with barely enough time to get ready. Thomas was at the house booking flights home for everyone, and after helping a bit, I grabbed my stuff and headed out to Undercity.

Took the metro, walked a bit, and then suddenly I was here. surrounded by nearly 200 other hackers ready to build and ship.

What Is Undercity?

Undercity is a multi-day hardware-focused hackathon hosted at GitHub HQ, run by Hack Club. It’s the latest event under the umbrella of Highway, a summer program supporting students in building ambitious, creative projects.

Undercity is intense, inspiring, and packed with projects. Think:

• Hackers sleeping on the floor
• Real deadlines
• Free meals
• Tables overflowing with Arduinos, Raspberry Pis, sensors, and endless spools of wire.
• Plushie prizes
• And more unforgettable moments than you can count

Meeting the atendees

When i arrived together with SPC i went strait to talking to people, some new some i already knew. I also saw the organizers helping to run the event and make sure everyone had what they needed. it was all very fun and an exiting start!

Starting Presentation

The opening presentation set the tone for everything to come:

• Build a hardware project
• Top 10 get plushies
• First place gets a 3D printer
• Second and third place get secret prizes

I didn’t officially join a team. I just wanted to enjoy the experience and get away from what Neighborhood had become. I loosely teamed with SPC, but mostly I floated and had fun. And honestly? That worked out really well.

The Rest of Day 1

The rest of the day I mostly sat next to SPC, who helped the organizers with badges, talked with people, and soaked in the creative atmosphere. It was just a great time.

Morning Vibes

Despite sleeping on the floor, I had a surprisingly great night's sleep. My hip hurt a bit from laying on my side, but it was still a good night. Right after waking up, the demos started. One team built a working chocolate 3D printer. Yes, really. Chocolate. It was incredible to see it working.

Refresh and Reset

I quickly went back home to shower, shave, and generally not feel like a mess. On my way back to GitHub HQ, I walked past a Dodgers vs. San Francisco Giants game.

It was cool to see that part of American sports culture up close. My grandfather would’ve loved this moment. Ik hou van je, opa.

Time Flies

These Days all just went to fast, and with a blink of an eye. its already day 3

I Had Lunch with John Cohn

I met John Cohn without realizing who he was. We grabbed Chipotle together with him and a few other people and had some amazing conversations.

He gave me a Sam Stone, a tradition he’s known for, and shared personal stories full of meaning.

John is the kind of person everyone deserves to meet at least once. Sadly, he was leaving the next day to set up a massive light show. I’ll miss him.

Rooftop Views

After lunch, we headed to the rooftop of GitHub HQ. Beautiful views, deep conversations, and that surreal feeling of being somewhere really special.

Zach

Zach Latta is the founder of Hack Club. and easily one of the most inspiring people I’ve met.

He started Hack Club because he wanted teenagers to feel like they could build real things. Not school projects. Not assignments. But things that matter.

Talking to him in person reminded me that this whole thing. Undercity, Neighborhood, even Juice last year. exists because he believed kids like me could do more than just sit in a classroom.

He listens, he encourages, and he genuinely cares.

This week has been chaotic, emotional, beautiful. and somehow, it all still feels like just the beginning.

Final Demos

Today was the big one. The final demos.

The room was buzzing with energy. everyone setting up their projects, helping each other troubleshoot last-minute bugs, and rushing to finish details. Despite the chaos, it was beautiful.

There were so many cool things to see: A glove that was a controller for a game. A glowing LED cube running a game of Snake. And the winner? A toilet paper folder. Yes. That won first place. And honestly? It deserved it. The presentation was on point xD

After the demos and voting, we had one last group presentation, followed by the awards. People clapped, laughed, celebrated their work. The team that made the chocolate printer even got into the top 10

And then… it was over.

We cleaned up the space, packed our bags, and stood around in small circles, not quite ready to say goodbye.

Goodbye

The last few days have been unmatchable. Not just fun. but something deeper.

This week has been the best time I’ve ever had. By far.

I didn’t expect that. I came here after the chaos of Neighborhood, just hoping for a soft landing. What I found was something close to magic.

Spending time with these people, building, laughing, dancing, sitting on the floor writing code at 1am... it felt like I belonged in a way I haven’t felt in a long time.

The organizers did a great job making everyone feel seen and included.

It hurts to let go of this. But I know I’ll carry it with me. The people. The memories. The feeling of building something that matters.

Thank you, Undercity. You changed me.