What Klarna CEO Sebastian Siemiatkowski Wants Every Founder to Know

Before Klarna became one of Europe’s most valuable fintech companies, before “buy now, pay later” became a global movement — Sebastian Siemiatkowski was a high school graduate scrubbing floors in Sweden.

On the Acquired podcast, Klarna’s co-founder and CEO laid bare the mindset that got him from janitor to unicorn builder. But this isn’t a story of overnight success. It’s a study in conviction, risk, and relentless self-development.

“I was 17, cleaning at Burger King, and I realized — this isn’t the life I want,” Sebastian said. “I wanted to build something meaningful. And I didn’t have a Plan B” .

Here are the founder principles that helped him go from cleaning up messes to reshaping the payments industry.

1. Don’t Ask for Permission — Start Before You’re Ready

When Klarna launched, Sebastian didn’t have a finance degree or connections in banking. What he had was a sharp insight: the payments experience in Europe was broken.

So he acted.

“If we had waited until we were ‘qualified,’ Klarna would never exist,” he said. “Start now. Learn by doing” .

For founders, this is a crucial reminder: expertise can be built. What matters most is execution.

2. Grit > Talent

Early on, Klarna didn’t take salaries. Sebastian and his co-founders survived on student loans. The business was bootstrapped with no venture capital in sight.

“I’d bet on grit over talent any day,” Sebastian said. “The ability to endure and push through is more predictive than IQ” .

In a world that glamorizes genius, Klarna’s story is a grounded antidote. It's not about being the smartest in the room — it’s about being the last one standing.

3. Feedback Is a Mirror — Use It

Sebastian is unapologetically introspective. Throughout the ACQ2 interview, he emphasized self-awareness as a founder’s superpower.

He once hired a coach to help him understand how he showed up in meetings. Why? Because feedback, he realized, is not judgment. It’s information.

“The faster you learn what’s working and what’s not — about your product and yourself — the faster you grow,” he said .

4. Culture Is Not an HR Function — It’s a Daily Discipline

Klarna is known for its intense, feedback-heavy culture. Some love it. Some don’t. But it’s not accidental.

“We wrote down our values early. And we live them, even when it's hard,” Sebastian said .

This is a message every founder should hear: company culture isn’t what you say it is. It’s what you do when pressure hits.

5. Bet Big — But Be Ready to Course Correct

Sebastian doesn’t sugarcoat it. Klarna has made mistakes — including underestimating economic cycles and over-expanding during low interest rate years.

But he never stopped thinking like a founder.

“You have to be bold. But you also have to take responsibility when things don’t go your way,” he reflected .

Risk isn’t the enemy. Denial is.

Final Thought: No Plan B

Sebastian Siemiatkowski didn’t build Klarna by playing it safe. He built it by refusing to give up.

His advice for new founders?

“Make sure you care about what you’re building. Because if you don’t, you won’t survive the lows. And there will be lows” .

It’s not a story about instant success. It’s about showing up — again and again — until the world takes notice.