About

My story.

As a kid, I built worlds. Today, I treat cancer with beams. In between, there's a detour I hadn't planned.

My name is Julien Welmant, radiation oncologist. As a kid, then, I built worlds. Lego kingdoms, stories written in squared notebooks, games invented for my cousins. I devoured fiction. I loved Pokémon. Anything that could take me somewhere else captivated me. That taste never left.

Then came Japan. My first trip, at eighteen, to celebrate my high school graduation. Back then you knew almost nothing before arriving. No YouTube, no Instagram, few blogs. You really went in blind.

I've been back a dozen times since. Sometimes for work, often just for me. It became my personal retreat, the place where I feel right. I return with the same wonder as the first trip. Japan changed the way I look at people, objects, life. It infuses almost everything I do, even without saying so.

I practiced medicine the classical way for a long time. Then one morning I understood I had stopped building. I was doing my job well, but the kid who used to build worlds was no longer building anything. So I started again.

What I'm looking for today fits in one sentence: make health desirable. Not a burden you endure, not an obligation you avoid. Something that can be beautiful, engaging, sometimes even joyful. I call it Health Should Be Fun. People smile when they first hear it. Then they think, and they stop smiling. Because behind the phrase there's a serious conviction: a care system that isn't desirable is a system that fails before it even starts.

That conviction gave rise to Miroki, the world's first care pathway with a humanoid robot for children in pediatric radiotherapy. It gave rise to ATLAS, the sovereign on-prem AI assistant in my clinic. And with my friend Sylvain, Médecin Malin, the newsletter helping other doctors not drown in tools.

None of these projects stands alone. That's why they hold.

Treating, building, writing, being a father too. To carry all of that without burning out, I ended up building a system. A personal tool that absorbs, connects, challenges, remembers. It's not ready to be shown yet. But it's what makes everything else possible.

My daughter brings me back to what matters every day. What I build, I build first for a world she will inherit. If tomorrow care there is a little more human, a little more alive, a little more meaningful, that will not be nothing.

On this site you'll find my projects, my ideas, my attempts. Pieces of a single puzzle slowly taking shape.

A hospital of the future, maybe.

If one of these worlds speaks to you, write to me on X or LinkedIn.