Business Athletes: Sijbrand Tieleman

Hello and welcome to Business Athletes everyone 👋 

Each week, we’ll explore the athlete-like habits behind a different business leader.

In less than 5-minutes, we aim to provide you with practical tactics that you can quickly apply in your day-to-day.⚡️

This week I sat down with Sijbrand Tieleman, co-founder & CEO of Proba.Earth, a climate tech company tackling emissions in one of the most overlooked but high-impact industries: fertilisers.

Sijbrand isn’t your typical climate founder. He didn’t come from climate. He spent decades leading B2B IT firms and fintech ventures before stepping into one of the most critical and underserved sectors in climate.

From our conversation, it became clear that what sets Sijbrand apart is his resiliency.

Maybe that comes from being an avid cyclist, or his obsession with tracking his health and recovery with an Oura ring.

In a sector that moves slowly and demands long-term resilience, he brings a high-performance approach that’s grounded, human, and built to last.

Let’s get into the full conversation!⚡️

Pre-Game Preparation

Morning Flow In Movement

I live in Amsterdam, so most mornings start with a bike ride. It’s a 30-minute commute to the office, which doubles as my mental reset. While I’m cycling, I usually throw on a podcast - maybe Invest Like the Best, 20VC or Lenny’s Podcast.

I'm not too precious about the morning ritual. Sometimes I’m already reading emails or catching up on things before I’ve left the house. By the time I get to the office, I’m usually the first one in. No coffee machine warm-up, no distractions. Just water, laptop, and into the work.

Deep Into The Game

Building Thematically In A Team

We’re a small team of eight people, and we made the call early on to build the company in-office. Everyone comes in most days. There’s a standing joke that everyone gets one “laundry day” a week to work from home.

I like it that way. Face time matters. Being around each other, especially when you’re working in an emerging market like ours, helps build trust and momentum.

That said, my day isn’t ruled by structure. Aside from our Monday-Wednesday-Friday standups and one weekly customer-focused sync, my calendar stays fairly fluid.

Instead of blocking themes per day, I break down the week into thirds:

• A third is customer-related work: external conversations, feedback, value delivery.

• A third is commercial: BD, partnerships, new client acquisition.

• And a third is forward-looking: capital strategy, future planning, pitch decks, and vision.

His Championship

Tackling Climate, From a Different Angle

Before Proba.Earth, I co-founded a B2C fintech company. Before that, I was in B2B IT. So when I decided to work on climate, I was entering uncharted territory. I just knew this was the biggest problem of our time — for our generation, our kids, and hopefully our grandkids!

We didn’t start out in fertilisers. But once we stumbled into it, through conversations, contracts, and research…it just clicked. The emissions are enormous. The industry is global but still fragmented. And there’s surprisingly little innovation being applied, despite the massive impact.

Most importantly, people know each other in this space. You don’t need huge marketing budgets to get noticed if your product and credibility are strong.

Being the Outsider As An Advantage

I’m not from this world. I’ve never worked in fertilizers before. But I’ve built companies. I know how to operate lean, how to raise capital, how to deal with setbacks, how to create trust across long supply chains. And that’s valuable here.

In fact, we’ve managed to sign a partnership with the International Fertilizer Association (the global industry body). It’s the first time they’ve done something like this with a startup.

That only happened because of the relationships we built, not just the tech. In climate, people underestimate how human this business still is.

The Business Athlete Mindset

Mastering Focus

Lately, I’ve also realised something else: being too future-oriented can be dangerous. With all the hype around AI and other frontier tech, it’s easy to panic.

But what I’ve learned is: change matters, yes. But so does focus. Being steady. Being predictable. Not chasing every shiny object.

Staying The Course

The biggest challenge has always been the timelines. In our industry, things move slowly. Factory changes take years. From first talks to actual implementation, it’s a 3-5 year cycle.

So, I’m not romantic about startups. We’ve been through tough cash cycles, and I’ve learned not to scale too fast.

Our goals are simple:

1. Make what we’re doing truly scalable and high-impact.

2. Stay alive long enough to do it.

Especially in climate and deeptech, trust comes from reliability, and reliability comes from long-term thinking. So, that’s what we’re trying to do with Proba.earth. Build something that actually works for the long-term — not just in theory, but also in the field.

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