How an Engineer Became a Solo Founder
The story of an engineer launching a startup alone in Japan. Why go solo, how AI-native development makes it possible, and the origin of R3O Works.
What Is a Solo Founder?
A solo founder is someone who starts a business without co-founders. It’s common in Silicon Valley but still rare in Japan.
I’m an engineer who chose to build products alone and ship them to the world. This is the story of R3O Works.
Why Start a Company
The reason is simple. I wanted to build what I wanted to use.
Every time I used an existing service, I’d think, “If only this worked differently.” But instead of filing feature requests and waiting, I could build it myself. That’s the privilege of being an engineer.
A regular job offers stability. But to bring “this could be so much better” ideas to life, I needed a place where I owned every decision.
The Origin of R3O Works
R3O is named after Leo, my late dog.
Leo was family. He was always there, unconditionally. The name R3O Works carries the trust and optimism he gave me.
Some might think a personal story doesn’t belong in a startup name. But when you’re building something alone, you want it anchored to what truly matters to you.
Why Solo
“Can you really do it alone?” I get asked this a lot. My answer: in 2026, yes.
The reason is AI. With tools like Claude Code as a development partner, one person can handle full-stack development. Design, implementation, testing, deployment. Work that used to require a team can now be done solo.
The greatest advantage of a solo founder is decision speed. No meetings. No consensus-building. The moment an idea hits, you can start coding. Even a small team can’t match that velocity.
There are weaknesses, of course. Marketing, sales, customer support – you do it all yourself. But that’s not “impossible.” It’s just “something to learn.”
The First Goal: $700 a Month
I’m not trying to change the world overnight.
The first goal is $700 in monthly revenue. Build one product that sustains one person’s life. Then ship the next one, and the next.
The first product is Shutter, a note-taking app built around speed, focused on writing and finding. It’s set to launch on April 27, 2026.
Solo Founding as a Viable Path
Few people in Japan start a company truly alone. But in an era where AI-native development is the norm, the barrier to solo entrepreneurship is lower than ever.
All you need is technical skill and a problem you genuinely want to solve. With those two things, one person is enough.
R3O Works is just getting started. I’ll be sharing the journey on this blog.
See Shutter’s product page | Why build a new note-taking app now? | What is AI-native development?