Heather Devereaux
April 25, 2022
7 min read

Shaping Founder Fundamentals Through a Startup Journey and Successful Exit

Could you be a great founder? Our Top 5 picks for Founder Fundamentals you need to be successful

How our experiences with Sentinels shaped our approach to founder assessment and support

  • The Sentinels origin story with a founding team focus
  • Could you be a great founder? Our Top 5 picks for Founder Fundamentals you need to be successful

As announced today via the Irish Times, Irish regtech unicorn Fenergo has finalised their acquisition of our beloved first venture, Sentinels. This is huge, emotional news for so many reasons. We’re deeply proud and thrilled for the Sentinels founding team of Joost van Houten, Arryon Tijsma, and Friso Paping, whom we’ve had the joy and pleasure to support over the past 2.5 years. Alongside the entire Sentinels team, they’ve built an incredible company, culture, and AI-powered product. We can’t wait to see what they do next!

Early days of Sentinels with Friso, JC, Heather, Bart, and Joost

We’ve talked before about how our experience building the Sentinels AI-powered product facilitated our pivot to a venture studio. But our experiences building Sentinels shaped us in other ways, such as how we spot, assess, complement, and support founders on their early journey for the greatest possible chance of success. So many people I speak with wonder if they have what it takes to be a great founder. For those of you still considering the entrepreneurial path, I hope you’ll see yourself in the coming paragraphs and that I inspire you to take the leap!

Where it all began…

I was impressed by Joost from our first introduction, and our meeting was instrumental to my joining Slimmer AI. Joost had just returned to The Netherlands from California, where he had recently joined a condensed study program about software product management. What struck me most was his (seemingly) nonstop industry outreach calls. He was on conference calls constantly: speaking with dozens and dozens of senior executives and business leaders about the problems they faced.

He was obsessed with finding and solving a real customer problem.

As fate would have it, a real customer problem was brewing. Slimmer AI had been working with Mollie on a project to address scalable transaction monitoring, and Joost instinctively saw much broader potential. Compliance professionals with a passion for crime fighting were forced to spend their days under an avalanche of meaningless alerts. Banks and fintechs were spending millions of dollars on this problem but it wasn’t getting any better. Couldn’t this be solved by using the power of applied AI?

Joost looked for technical and entrepreneurial minds to take this thinking further.

Weekly, we’d take the train to Groningen to meet up with gifted machine learning engineer and tech lead Arryon and the rest of the Slimmer AI tech team. There we brainstormed and dreamt up exactly how data and AI would win this market in the years to come. Soon adding ‘Swiss Army Knife’ Friso to the crew, we spent many evenings talking through what problems Sentinels could solve, how would we build it, who we’d sell to next, and what sort of company he wanted to create.

I’d also like to specifically acknowledge the support of industry experts Maikel Lobbezoo and Adriaan Mol, who were invaluable to Sentinels’ early success. Without Adriaan, our first proof-of-concept would not have been possible; and without Maikel, the bigger vision would have been much less compelling to early customers.

Our favourite spot to problem solve: the fireplace at Hotel De Doelen in Groningen.

What we look for in founders (and what we saw in Joost)

We began this journey with Joost with the strong belief that we were in the right market, with the right customer, working with the right team, with the ability to provide the right technical and business-building support.

In Joost we saw what I like to call “founder fundamentals.” And we weren’t the only ones to notice! After investing in Sentinels, investor Kyang Yung of Inkef Capital said:

“In our interactions with Joost, what we found was an enormous level of ambition, deep domain knowledge, and a natural charisma that has already helped the company attract strong leaders from the fintech and payments industry.”

Founder Fundamentals

There are many on-ramps to the entrepreneurial superhighway. And exceptional founders come from so many diverse backgrounds. Through helping Joost, Arryon, and Friso launch Sentinels, as well as our work with Biller, Vesper, Hadrian (and a few still under wraps!), we’ve gotten quite skilled at spotting and stoking the fire needed to succeed in venture building.

We’ve codified our lessons, as well as the lessons from Europe’s top tech-scale ups, into a proprietary framework and customised experience to help assess and guide founder development.

To help all of you budding entrepreneurs, here is my list of the Top 5 qualities needed to succeed as a founder:

1GRIT It’s described many ways: drive, perseverance, tenacity, fire. Simply put, the ability to keep going — overcoming obstacles and challenges — is a must-have founder skill.

Like all start-ups, Sentinels had its moments of “near death”, but Joost’s confidence, determination, and calm never wavered.

2VISION Great founders have a vision of where they want to go. Even though you might be on a roller coaster ride, you need a clear view of what success will look like across many aspects. Where do you want to be? What do you want your company to be like? What customers do you want to win? Then be sure to articulate this vision clearly and compellingly.

Between interviews with candidates and pitches to investors, Joost became an all-time champion of sharing his vision. One of our favourite tactics for developing this mindset at Sentinels was using the Amazon approach of writing a future press release. It works!

3SELF-AWARENESS Ancient Greeks preached the wisdom of Know Thyself, the ability to objectively see oneself for all our strengths and challenges. Self-awareness will help you see that you’ll need others on this journey. Know what you don’t know and what you are not good at; and then build a team around you to complement you!

Early on, Joost realised he’d need some more ‘street cred’ to complement his young enthusiastic team. He looked for experienced, seasoned professionals with deep expertise to help him scale customers and technology alike. He first hired Stefanie, an experienced customer success person, with a very different way of thinking and engaging with customers than himself. And then brought Ibrahim onboard, a strong engineering leader with substantial experience in scaling product and engineering teams.

4DECISIVENESS For founders, decisiveness (decision + speed) is a key muscle to build. After all, the only decision worse than a poor decision is no decision at all. At Slimmer AI, we supercharge decision making by applying agile methodologies to all parts of our business and through merciless prioritisation using the Critical Path framework.

Joost and team always had more opportunities than they could handle — in new geographies, different segments, adjacent product modules — but he has the discipline to take a decision and execute against it.

5EMPATHY Research shows empathetic leadership can have direct business impact on everything, such as innovation, retention, and measures of inclusiveness. The ability to put yourself in someone else’s shoes and think about how they might be feeling goes a long way to drive these outcomes.

It’s a muscle worth developing, and we’ve seen Joost exercise this skill as the team grew. I remember in the very early days it wasn’t easy for him to show some vulnerability to his team, as his instinct was to project confidence. This is a very relatable moment for many of us. But I saw him really unlock his leadership potential when he brought the team closer. Because as is often the case, your team will have the answer if you ask them for help.

As a venture studio, we get the benefit of ‘compounded learnings’ that new founders can leverage — including our insights into what it takes to succeed.

We’ve learned so much building Sentinels and Biller (check out some of our lessons learned from co-building Biller here). And we continue to learn tons from working with the founders of Vesper and Hadrian as they scale.

We have started applying our efforts to build our next venture from scratch with two amazing female founders (more on this endeavour soon). And we’ve scaled up our capacity to be able to build 2–3 more ventures this year.

Slimmer AI’s next founder: Is it you?

At Slimmer AI we believe in two things: the power of AI to improve people’s work; and the power of working with the right founders to build new companies. It’s these founder stories — these human stories — that excite me most about my work at Slimmer AI.

Together with the team at Slimmer AI, I am excited to work with you to help you make your entrepreneurial dream a reality! If you’ve seen a problem that must be solved with a product or company, ideally by applying AI, and are driven to make a real difference in your industry, I’d love to hear from you. Reach out directly on LinkedIn or Twitter.