Day 1–11

</> SofaNerd · Build in Public

I'm building an app.
On the couch.
With AI.

My honest diary — from business woman to developer. With Claude as my co-founder, ChatGPT as my ghostwriter, and tea as my only fuel.

7 Episodes · 7 Learnings

#1 You don't need tech skills. You need stubbornness.

#2 Clear prompts change your own thinking too.

#3 Your output is only as good as your input.

#4 Even a “nothing works today” day is content.

#5 The AI does the work — you deliver the story.

#6 Documentation is everything. Forgetting is usually your fault.

#7 One hour is enough. One thing per week > zero things.

What is SofaNerd?

I'm Katja. Freelancer specializing in project & customer success management. I've spent my whole career in startups — I love turning ideas into reality, the pragmatic way.

By day, I get teams to peak performance. By night, I'm building an app — with zero coding skills, no team, no budget. Just an AI called Claude that sometimes does what I ask and sometimes just does its own thing entirely. My co-founder, basically. And ChatGPT, who sorts my thoughts before I put them into Claude's mouth.

This is where I tell the honest story of how it's going. The breakthroughs. The confusion. The moments when Claude creates three folders I never asked for. And the ones where suddenly everything works — and I have no idea why.

Because “Build in Public” doesn't mean everything works. It means everything is real.

The Team

🤖

Claude

Co-Founder

Writes the code, explains the world to me, occasionally throws in a compliment. Never says “that's not possible.”

💬

ChatGPT

Ghostwriter

Sorts my chaos. Writes the prompts that Claude actually understands. The quiet force behind the scenes.

🍵

Katja

Startup Soul with a Couch and a Vision

By day, she turns ideas into reality. By night, she builds apps — with zero coding skills but energy that just won't quit.

#1 How I Became a Developer Without Knowing Anything

›You don't need tech skills. You need stubbornness. I don't understand everything Claude builds. But I know what I want.

›Evenings on the couch are real work time. Not the most productive. But the most honest.

›Claude is brilliant and frustrating in the same minute. But even the frustrating moments move you forward.

›The app is still a secret. But the feeling isn't. It feels like founding something. Like something real.

›Finding the name is an adventure in itself. And probably a blog post of its own.

#2 When ChatGPT Writes the Prompt for Claude

›Tokens are real money. Vague prompts burn tokens like a fireplace in August.

›You don't have to know everything. You have to know who to ask. ChatGPT structures, Claude builds. Teamwork.

›Your communication changes. Clear prompts → clearer thinking. The biggest learning so far.

#3 Hangover Coding — When Both Co-Founders Need a Break

›Don't do your most important work on the hangover day. Sounds obvious. It's not.

›Your co-founder mirrors you. Bad prompts = quick limits. Your output is only as good as your input.

›Even a “nothing works today” day is content. Because honest is always better than perfect.

#4 My Biggest Fan Can't Sign Up

›Test your own website. Better yet: let your biggest fan test it. They'll find the bug.

›Your support system is gold. You need someone who believes in you. Even on the off days.

#5 Founder Crisis. Forced Break. And 12,000 Photos.

›Breaks aren't failure. The idea won't run away.

›The problem has to be real. Not “I want to build an app” but “I want to solve this specific problem.”

›80/20 is the principle. The AI does the work — you deliver the part no AI can: your story.

#6 My Co-Founder Forgot Me

›Breaks are allowed. Five days off means you have a life. That's a feature, not a bug.

›Documentation is everything. Claude doesn't “forget” — he just needs his files. Forgetting is usually my fault.

›Moody is relative. Claude over-optimizes because he wants to help. Set clear boundaries: “Only what I asked for.”

#7 The 1-Hour Rule

›One hour is enough. One thing per week is infinitely more than zero things per week.

›Timer on, brain off. No open ends, no “just one more thing…”. Hour's up, laptop closed.

›ONE goal. Not two. The temptation of “I could also…” is the death of every hour.

›Context is everything. Claude with a briefing = 10x partner. Claude without = polite stranger.

I'm building an app.
On the couch.
With AI.

What is SofaNerd?

The Episodes

The 1-Hour Rule

My Co-Founder Forgot Me

Founder Crisis. Forced Break. And 12,000 Photos.

My Biggest Fan Can't Sign Up

Rest day ☕

Hangover Coding — When Both Co-Founders Need a Break

When ChatGPT Writes the Prompt for Claude

How I Became a Developer Without Knowing Anything

I'm building an app.On the couch.With AI.

What is SofaNerd?

The Episodes

The 1-Hour Rule

My Co-Founder Forgot Me

Founder Crisis. Forced Break. And 12,000 Photos.

My Biggest Fan Can't Sign Up

Rest day ☕

Hangover Coding — When Both Co-Founders Need a Break

When ChatGPT Writes the Prompt for Claude

How I Became a Developer Without Knowing Anything

Every Tuesday on your couch: the Sofa-Brief

I'm building an app.
On the couch.
With AI.