Facts
- ZIZ Foundation
- FTE: 8,3
- Growth Phase: Start-up
- Revenue: €1.3 million (2024)
For medical microbiologist Bas Mourik, this is his first venture as an entrepreneur. And for Greyt Controller Roy van Hagen, it’s his first role as a CFO. Together, they are scaling an innovative healthcare concept with one goal: making STI care faster, more affordable, and accessible to everyone. What started as a project has now become a rapidly growing start-up.
STI Care: Everything Under One Roof
Bas Mourik, founder and director of ZIZ Foundation (Zinnige InfectieZorg), corrects himself during the interview when referring to the second location in Utrecht as “a critical project phase.” It’s no longer just a project—it’s a fast-growing company.
“I started this project at LUMC (Leiden University Medical Center) during my medical microbiology training. But we’ve moved beyond the ‘project’ phase and are now working towards becoming an independent healthcare provider as quickly as possible. I didn’t take the traditional path of a medical microbiologist,” Bas says with a smile.
ZIZ offers a streamlined approach to STI care, where the entire process—from diagnosis to treatment and aftercare—takes place under one roof. This saves time and, ultimately, healthcare costs. Initially, Bas estimated the cost savings at €1 million per location per year, but in 2024, the realized savings exceeded expectations, reaching €1.3 million.
“Finance is essential—it has to be in order before you can grow. The level of insight we now have thanks to Greyt is invaluable.”
– Bas Mourik, Founder & Director, ZIZ Foundation
Stepping in as a Fractional CFO at a Start-up
With a growing patient base and plans to scale to multiple locations, ZIZ evolved into a full-fledged organization, bringing along all the financial and operational complexities that come with growth. That’s when Bas decided to bring in Greyt.
“We needed a clearer financial picture. The last thing I wanted was to have everything in place on the healthcare side but run into trouble due to something like a VAT issue.”
This is where Roy van Hagen came in. For Roy, this was his first role as a Fractional CFO, stepping in to provide flexible financial leadership. He now dedicates one day a week to ZIZ:
“I oversee Finance from A to Z and drive financial and HR optimization. I also focus on regulatory compliance and HR matters, allowing Bas to dedicate more time to strategic and operational growth.
At first, my role was mainly about creating clarity: How is revenue developing? What does our cash flow look like? Can we meet our financial obligations? And, importantly: How do we raise funding?”
“I make sure Finance is running smoothly and that Bas knows exactly which levers to pull.”
– Roy van Hagen, Greyt Controller & CFO
Navigating Growth & Expansion
What’s it like for Bas to go from handling everything himself to working closely with Roy? “It’s been great. Ideally, I’d also have dedicated support for IT and HR. But Finance was the priority. We now have better insight and control, allowing us to fine-tune our strategy and assess risks more effectively.
With restructuring and scaling happening simultaneously, we need to navigate carefully. Should we open new locations to generate more revenue and cover costs? Or should we consolidate first and then expand? That’s exactly where Roy’s expertise comes in.”
Roy adds:
“The key is to present financial insights in a way that gives Bas an instant overview: the big picture, the financial performance per location, cost variances, and the underlying causes. This allows us to fine-tune strategies and make adjustments in time. My job is to ensure that Finance runs seamlessly so Bas can focus on growth without distractions.”
Breaking the Traditional CFO Stereotype
Judging by the energy in the interview, the partnership is going well. Roy agrees:
“Yes, and it’s great to see that Bas no longer has to worry about Finance. We constantly check in to see where my expertise is needed most.”
Bas is equally enthusiastic:
“Finance is essential—it has to be in order before you can grow. The level of insight we now have, and how we can actively steer our financial strategy, is invaluable. I’ll be honest: working with Greyt is an investment, but one that delivers real results.
The phase we’re in now carries risks, so having someone by my side who understands this is incredibly reassuring. Plus, I have a great connection with Roy—he’s an excellent addition to the team. Thanks to him, the outdated, ‘boring’ CFO stereotype I once had is completely shattered.”
