This is a snapshot, not a manifesto. What one person can ship changes every six months as the tools evolve. This is what it looks like right now, from a one-bedroom apartment in Berlin, in March 2026.

My back aches. Not from exercise — from sitting in the same chair for eleven hours building something that didn't exist yesterday. The ache is familiar. It's the body's way of saying: you forgot to be a person today. I forgot. I usually forget when the building is going well.

Berlin is a good city to build alone in. Not because of the startup scene — Berlin's startup scene is fine, not exceptional. Because of the anonymity. Nobody in my neighborhood knows or cares that I'm building AI tools from my living room. The döner shop downstairs doesn't know I run a hotel brand. The woman who runs the Späti doesn't know I publish in two languages to thousands of people. This invisibility is a feature, not a bug. It means I can fail without an audience and ship without permission.

Here's what I shipped this year, alone:

A content automation tool (Soulin Social) that generates, schedules, and publishes across four platforms. A sales agent for KINS that handles inbound leads, qualifies them, and books calls — I built this in three weeks using AI coding tools. An updated membership site with Stripe integration, tool access gating, and automated onboarding emails. A complete Substack publication with 30+ essays in two languages, organized into three narrative threads. This essay you're reading now.

None of this required a team. All of it required patience, stubbornness, and the willingness to ship ugly first versions.

In "The Soulin OS," I wrote about the framework underneath the building. In "How AI Runs My Entire Business," I wrote about the tools. This essay is about the city — what it's like to actually do this work, day after day, in a specific place.

A typical building day in Berlin:

9am: Wake up. Coffee from the kitchen, not a cafe — cafes are for writing, not building. Check what Soulin Social drafted overnight. Review, edit, approve. 30 minutes.

10am-1pm: Deep building block. Whatever the current priority is. Right now it's improving the KINS booking flow. This block is sacred — no email, no messages, no social media. The phone is in the other room.

1pm: Walk. Berlin is flat and green and good for walking. The Landwehrkanal is ten minutes away. I walk along it and think about nothing, or everything, or the specific bug I couldn't figure out before lunch.

2pm-5pm: Second building block. This one is usually lighter — emails, content, administrative things. The creative energy peaks in the morning and declines by afternoon. I've learned to schedule accordingly.

5pm: Stop. This is the hardest part. The building wants to continue. The body wants to stop. I've learned to trust the body. It knows more than the building does about what I can sustain.

Evening: Sometimes I write. Sometimes I read. Sometimes I sit on the balcony and watch the sky turn pink over Kreuzberg and think about how strange it is that this is my life — a Korean woman in Berlin, building AI tools alone, running a hotel brand on another continent, documenting it all for strangers on the internet.

What Berlin gives a solo builder that other cities don't:

Low cost for a European capital. My rent is below average. My total living expenses are lower than they'd be in London, Paris, Amsterdam, or any major US city. This matters when you're bootstrapping.

Cultural permission to be weird. Berlin doesn't care what you do. It doesn't care if you work unconventional hours, dress unconventionally, or live unconventionally. This sounds trivial until you've lived in a city that does care.

Soulin members get the full essay library, private group chat, the Soulin OS e-book, and every tool — all for $10/mo. Join Soulin →

Full essay library · Private group chat · Soulin OS e-book · Every tool · $10/mo

Functional infrastructure. Reliable internet. Public transit that works. Healthcare that doesn't bankrupt you. These are the boring foundations that make solo building possible. You can't ship products if you're fighting bureaucracy for basic services.

Distance from hype. Berlin has a tech scene but it's not dominated by it. I'm not surrounded by people talking about valuations and exits. The conversations here are about art, politics, food, and occasionally technology. This keeps me grounded in what I'm actually building instead of what I'm supposed to be building.

What Berlin doesn't give:

Sunshine. The winters are gray and long and they affect everything. I've learned to compensate — vitamin D, full-spectrum lights, acceptance — but the darkness is real and it costs energy.

A Korean community. There are Korean people in Berlin, but the community is small. Sometimes I miss being surrounded by people who understand my cultural operating system without explanation. I cook Korean food alone and it tastes like homesickness.

Speed. German bureaucracy is legendary for a reason. Getting a freelancer visa took four months. Registering a business took three months. Everything that takes a day in Seoul takes a month in Berlin. I've made peace with it. Mostly.

The question I get most from other solo builders: "How do you know what to build next?" The answer is embarrassingly simple: I build whatever I need. Soulin Social exists because I needed a content tool. The sales agent exists because I needed to handle KINS inquiries without being available 24/7. The membership site exists because I needed a way to gate tool access.

Every product I've shipped started as a personal itch. The market validation is: does it work for me? If yes, I open it up. If other people use it, it becomes a product. If they don't, it stays a tool.

This isn't a strategy. It's a survival mechanism. And Berlin, with its anonymity and its low costs and its cultural permission to be strange — is the best place I've found to survive while building.

Where do you build? And does that place make the building easier or harder?

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I write about freedom, healing, and building alone. Tools for the journey → soulin.co