Developer's Diary

Google recently launched a similar 'Nearby' service, but they allow 24-hour posts. We are sticking to our 1-hour limit. Why? Because Double Stop isn't about tracking; it's about a 'Digital Signal Flare.' If you see a pin here, you know that person is there *right now*. That reliability is our soul.

I spent the weekend auditing our bundle size. In a world of 'bloated' web apps, getting Double Stop down to a 151 kB shared bundle felt like a victory for our users in Salzburg. A smaller app means faster loads on mobile data while walking through the Altstadt.

As we move into mid-April 📅, our focus has shifted toward refining the 'Social Signal.' We've implemented a new local content filter to ensure that the community remains focused on platonic, safe, and respectful connections. Being based in Salzburg, a city where you can walk 🚶 across the entire historic center in just 20 minutes, reminds us that technology should serve the human scale.

On a personal note, the 'Double Stop' spirit is alive in my own life. I recently made a great friend who plays the guitar 🎸 just like I do; now, I occasionally visit his place so we can play a song together. It's a reminder that these small, real-world sparks are exactly why we built this.

We aren't building a global 'social network' yet — we are building a digital lighthouse 🚨 for real-world interactions. Every line of code is a deliberate choice to prioritize your presence in the physical world over your presence on a screen.

I returned to Japan just a month before the world changed due to COVID. For a long time, my social circle was small—just one close, quiet friend whom I saw only occasionally. Life was predictable until a chance encounter at a local bar changed my perspective. A stranger at the counter simply asked, 'Want to drink with me?' That one question led us through three more bars that night and sparked a genuine friendship. When my future wife visited Japan, he welcomed her to our lunch with beautiful, thoughtful gifts—two pouches made from traditional kimono fabric. From that night on, we became 'neighborhood friends' who visited each other's homes. Knowing I had a good friend just a few blocks away changed how I felt about my community. That feeling—the security of a spontaneous local connection—was the second major spark for this app, joining the observation I had made months earlier in that Tokyo supermarket.

Double Stop is live. I have told almost nobody. I am not sure that is a strategy so much as just how I am. But I keep thinking about it: somewhere, someone posts that they are sitting in a café with their laptop, wearing a green scarf, there until four. Someone else sees it, unlocks it, walks in, sits down nearby, and says something small. It does not have to be important. It just has to happen.

I still think about the man by the mushrooms. I don't know if he was lonely. Maybe he was perfectly fine and just bad at shopping. But I think about all the people standing in their own version of that supermarket, hoping for a small opening that nobody provides. Double Stop is probably not a solution to loneliness. But it might be a small opening.

My wife asked what I hoped for with this. I said: I hope someone makes a friend they otherwise wouldn't have. That's it. One connection that wouldn't have existed without a slightly over-engineered app built in a flat in Salzburg. That would be enough for me.

I am not a product developer by training. I know enough to build something, and apparently also enough to make it take much longer than it should. Building Double Stop from scratch meant making a lot of small decisions I had never thought about before — how posts should expire, what to ask users for, how carefully to handle someone's location. I spent an embarrassing amount of time on the map picker. This is not something I am proud of.

One rule I set early: this would cost nothing to run. Not because I am especially frugal, but because I wanted it to keep existing without needing to grow or charge anyone. Leaflet instead of Google Maps. Nominatim for geocoding. A free Postgres tier. Every choice was basically the same choice: keep it alive without it needing to justify itself.

The first time it worked end-to-end — post created, post visible, post unlocked — I sat there for a moment. It was a small thing. It was also the thing I had wanted to exist since that Tuesday evening in Tokyo.

My wife and I moved to Salzburg on March 17th. It was her opportunity — a position she had worked toward for years — and I followed. Austria is very green. The mountains are bigger than I expected. Our apartment is small but has a nice window.

I knew nobody here. My German was not good. The city was fine to us in the way that cities are fine to strangers — not unfriendly, just not yet open. I would walk through the Altstadt and feel exactly what I had felt in that Tokyo supermarket: present, surrounded, and somehow not quite there. The irony was a little funny, honestly. I was building an app for this exact problem while living it every day.

I think it helped, in the end. The problem stopped feeling abstract. I had a specific café in mind. A specific feeling of sitting somewhere and not knowing anyone within a very large radius. I kept working on the app.

It was a Tuesday evening and I was standing in the produce section of a supermarket in Tokyo. The store was full — carts bumping, a child asking about something on a high shelf, the quiet shuffle of people deciding between two kinds of daikon. And yet, watching all of it, I felt completely alone. Not in a dramatic way. In a quiet, ordinary way that I think most people know but rarely say out loud.

I noticed a man around my age standing near the mushrooms, staring at them the way you stare at something when you've forgotten what you came for. I wondered if he was tired. I wondered if he was cooking for one. I almost said something — and then didn't, because there is simply no social structure that permits it. We were separated by nothing more than twenty centimetres and a complete absence of context.

That was the moment. Not a grand epiphany, just a small observation: we are surrounded by people carrying the same quiet thoughts, and we have no bridge. I went home that night and opened my laptop. I didn't know what I was building yet.