Rebel Spotlight: Manuel Prinz, AI Startup Co-Founder

He ate a fertilised duck egg at 8am in the Philippines and asked for seconds. That's probably all you need to know about Manuel Prinz. But there's so much more, so stick around.

Manuel is the co-founder of Keep Converting, an AI-powered e-commerce startup currently launching out of stealth mode in California. He grew up in a small town near Stuttgart, Germany, surrounded by Mercedes-Benzs and Porsches and a very clear social contract: go to school, become an engineer, work for a car company, repeat until retirement. He did not do that.

The Internship That Changed Everything

Manuel's dad, bless him, actually tried to help things along. When young Manuel announced he wanted to skip school and go straight into the automotive industry, his dad said not so fast and arranged an internship. Manuel showed up expecting some version of cool. What he got was hard labour, wrenches, and the slow realisation that mechanical engineering was absolutely not his thing.

"I was like, wait, is that the engineering job I'm supposed to do?" Manuel told me. "I was like, maybe that's not for me."

That internship, as bad as it sounds, was actually the gift. It redirected him into business and economics. And buried in the fine print of his university's course catalogue was a one-sided exchange programme with UC Santa Barbara. Nobody talked about it. Nobody used it. Manuel found it anyway, drilled down to make it happen, and got himself on a plane to California.

He's been there, more or less, ever since.

Explosions and Fireworks (His Words, Not Mine)

Manuel landed in the US in 2008 and described his first impressions with the kind of wide-eyed clarity that only comes from genuinely seeing something for the first time. The polished SUVs at the airport. The sheer size of everything. And then, a weekend trip to San Francisco with his roommates from the Bay Area, where he saw a single city block containing an investment banker, a skateboarder, and a person sleeping rough on the ground.

"I was like, how do these three worlds combine and exist in one block?" he said.

In Germany, he told me, everything was levelled. Same houses, same trajectory, same middle class. San Francisco was something else entirely. And what struck him most wasn't the chaos. It was the individuality. Everyone was chasing something. Everyone had their own dream. He wanted to be part of that.

After his studies, he joined a San Francisco tech startup called Paymentwall, an early-stage payments company sometimes described as a Stripe of its era. That job took him to over a hundred countries. (Yes, you read that right. A hundred-plus countries. I've been to maybe a dozen and I feel pretty good about myself, so that was humbling.)

What a Hundred Countries Teaches You

Manuel's travel philosophy is worth stealing. When he lands somewhere new, he does two things. First, he asks his taxi driver for a complete rundown of the city. "A taxi driver can give you in 15 to 20 minutes a complete rundown of what's happening," he said. "It's invaluable." Second, he finds a local bar on the first night, orders something, and just starts talking to people.

His favourite destination out of all of them? Vietnam. Specifically Hanoi, where their office had a chef who woke up at 4am, went to the market, bought fresh fish and herbs, and cooked breakfast from scratch every morning. Manuel showed up on day one, got handed a bowl of fish soup at 8am, almost declined, then ate the whole thing and immediately asked for more.

"It was mind-blowing," he said. "That's so good."

That moment, a German guy in Vietnam eating fish soup at dawn and loving it, feels like a pretty good metaphor for how Manuel moves through the world. He leans in. He tries the thing. He figures it out after.

Never Stop Running

These days Manuel is deep in building Keep Converting, which is coming out of stealth and heading into the market. Day to day he's juggling product, growth, and the endless problem-solving that comes with an early-stage AI company. He described his favourite part of the job as talking to other businesses and entrepreneurs, not because it's networking, but because it forces him to look up from his own work and see what's happening left and right.

His personal motto is simple: never stop running.

"If one day for me I stop running, then that would be the end date," he told me. "And I never want to get there."

He means it both literally (he runs a little, not miles, which is very relatable) and as a way of being. The anxiety he feels when he tries to do nothing on vacation, the two or three days his wife says he needs before he can actually settle into a holiday, that's not a flaw. That's the engine.

Advice for the Rebels in Waiting

I asked Manuel what he'd say to the people sitting on the edge of something, the ones who have an idea that won't go away but haven't acted on it yet. He didn't hesitate.

"Every time you want to do something or you have some idea, that idea is in your head for a reason," he said. "If that thought persists, even if you sleep at night and it's still there, it's there for a reason."

He talked about the trap of talking yourself out of things. You share the idea, someone gives you ten reasons it won't work, you feel validated in your hesitation, and you stop. He's watched it happen. He's felt the pull of it himself. His mom told him she stopped trying to argue him out of his ideas early on, because once something was in his head, it was done. He was going.

That instinct, to just go, took time to build. But it built. And it's the through-line of everything: the internship that redirected him, the exchange programme nobody else used, the fish soup, the hundred countries, the startup in stealth that's now stepping into the light.

Manuel Prinz didn't follow the path. He found the footnote in the programme guide, rang up a university in California, and asked if maybe, possibly, he could come over. They said sure. He got on the plane.

The rest is still being written.

Catch the full conversation with Manuel Prinz on The RebelRebel Podcast, including his take on why the journey is the goal, what he saw on that first San Francisco street corner, and yes, the full balut story.