Fortune Greece has named Sotiris Oikonomou, Founder and Managing Director of MarkApp, to its 40 Under 40 list for 2026, the magazine’s annual selection of the new generation of Greek business leadership.
The recognition arrives in the same month that VideoWeek’s European Video Awards named him Emerging Entrepreneur of the Year, capping a defining period for the founder and the company he built.
About the list
Now in its 14th edition, Fortune Greece’s 40 Under 40 recognises forty entrepreneurs under the age of 40 for innovation, international outlook, vision and the ability to turn ideas into business results. Fortune Greece is explicit that funding and turnover do not decide a place on the list; initiative, value creation and adaptability do. More than half of this year’s honourees work in technology. The full list is published on Fortune Greece and appears in the magazine’s November issue.
Why it matters
A list that values initiative over capital raised is a natural fit for MarkApp’s story.
Sotiris founded MarkApp at 22, with no loans and no venture capital, teaching himself code, product and sales along the way. Fortune Greece’s profile highlights exactly that: a company that has grown without external funding while building its own advertising technology across websites, mobile apps and connected TV.
A Greek founder, building globally
Originally from Greece and now based in Dubai, Sotiris has built a career across London, New York, Singapore, Tel Aviv and Dubai. MarkApp reflects that outlook, with offices in Athens, London, Limassol and Dubai and partners across Europe and the Middle East.
At its core is a full stack built in-house:
- Pantheon, a contextual SSP that monetises premium content environments for publishers.
- Harion, a cross-device commerce DSP that activates campaigns on every screen.
- MarkDash, unified reporting that keeps every partner fully informed.
A defining year
- Fortune Greece 40 Under 40: 2026 honouree.
- European Video Awards: Emerging Entrepreneur of the Year 2026.
- FT1000 2026: named in the Financial Times ranking of Europe’s fastest-growing companies.
- Best New Product: Pantheon shortlisted at the 2026 European Video Awards.
- Givsly Impact Awards 2026: finalist.
In his words
“Greece is where my story started, and the values I took from it, independence, hard work and ambition beyond borders, are the values MarkApp is built on. Being recognised by Fortune Greece means a great deal. I share it with our team, and with every young Greek founder building something of their own.”
Sotiris Oikonomou, Founder and Managing Director, MarkApp
What comes next
MarkApp continues to invest where advertising is heading: connected TV, contextual intelligence and premium content environments, built and run independently.
To explore what MarkApp can build with you, talk to our team.
