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Maest
Stijn Koster established Maest as the single family office that succeeded his operating companies. Koster founded i3D.net and Smartdc datacenters, scaled them...
Maest
Stijn Koster established Maest as the single family office that succeeded his operating companies. Koster founded i3D.net and Smartdc datacenters, scaled them to 100 million EUR ARR, completed six acquisitions and three exits to listed buyers, then moved to chairman and investment roles. The firm maintains a multi-generational mandate focused on capital preservation and continuity for the family. Maest allocates across private equity buyout funds, venture capital and deep tech funds, hedge funds, direct co-investments, LP-led secondaries and commercial real estate. It targets lower middle market private equity funds structured for participation exemption and multi-asset co-investment vehicles. Confirmed positions include Netherlands-based lower middle market funds and global venture allocations in AI/ML, cybersecurity and blockchain. The firm operates in Europe with additional exposure across North America, Asia, Africa, the Middle East and South America. It maintains a concentrated portfolio and adds only a limited number of new managers each year. No external capital or leverage is used. The team consists of Koster as founder and principal together with business partners Bo van der Putten and Jan Niessen from De Drie Mollen. Maest also runs a mixed-use real estate portfolio in the Netherlands and maintains philanthropic allocations to regional foundations and sports sponsorships. In the last 24 months the firm continued its pattern of selective private market commitments without disclosed leadership or structural changes. Maest's architecture differs from typical single family offices through its direct operating-company heritage. Koster's 29 high-growth awards and repeated exits created internal capital that now supports both fund commitments and board-level involvement in portfolio vehicles, allowing the office to act simultaneously as LP and governance participant without external fundraising cycles.
General information
Firm type
Single Family Office
Year founded
2008
Location
Region
Europe
Country
Netherlands
City
Capelle Aan Den IJssel
Corporate office
Capelle Aan Den IJssel, Netherlands
Principals
Stijn Koster
Founder
Altss tracks 2 additional named team members for this firm — including direct investment leads, IR, and operating principals not listed on the public website.
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Frequently asked questions
Who runs investment decisions at Maest?
Stijn Koster serves as founder and principal. Business partners Bo van der Putten and Jan Niessen support deal flow and governance from their roles at De Drie Mollen.
How does Maest source proprietary deal flow?
Access stems from Koster's long-standing relationships built during two decades operating i3D.net and Smartdc. The firm adds only a limited number of new managers annually and prefers capacity-constrained vehicles.
Does Maest participate in fund commitments or only direct deals?
Maest commits to lower middle market private equity buyout funds, venture capital funds and LP-led secondaries. It also executes direct co-investments and holds commercial real estate assets.
What investment stages does Maest typically target?
The firm covers buyout, growth, majority, middle market, seed and venture capital stages through both fund commitments and direct allocations.
Where does the underlying wealth come from?
Wealth originated from Stijn Koster's founding and scaling of i3D.net, a global hosting provider for online gaming, and Smartdc datacenters, both of which reached 100 million EUR ARR before exits.
Does Maest maintain philanthropic structures, and how are they separated?
Maest allocates annually to charitable foundations, local schools, municipalities and sports sponsorships. These activities sit alongside but separate from the investment portfolio.
What is Maest's known posture on co-investments alongside external GPs?
In select funds Maest takes advisory committee seats or acts as delegated board member. It favors alignment, transparency and governance in multi-asset co-investment vehicles.
Profile maintained by Altss using OSINT (open-source intelligence), regulatory filings, licensed data partners, and verified direct submissions. Read the methodology. Last updated: . Continuous refresh with full update cycles at least every 30 days.
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