Rogier Fischer

“I started hacking when I was 12,” Rogier Fischer said in October 2026. By his mid-teens he was reporting security flaws to Dutch banks and to Google, Microsoft, and Yahoo. Today he is co-founder and CEO of Hadrian, an Amsterdam, Netherlands company whose AI agents map a company's external attack surface and run pentests against it.

A Hacking Forum in 2009

Fischer met his future co-founder Olivier Beg on an online hacking forum in 2009, when they were both 13. Within a few years the two were working as white-hat hackers for Dutch banks and global tech companies, testing their defenses by hand.

LiteBit and London Business School

Before Hadrian, Fischer co-founded the crypto trading platform LiteBit and served as its CTO, growing it past $750 million in trading volume, he said. Hadrian describes LiteBit as one of Europe's first crypto exchanges. He met his third co-founder, Maurice Clin, while studying at London Business School.

Testing as Often as Companies Change

Fischer, Beg, and Clin founded Hadrian in 2021 after watching attackers adopt automation and AI while red teams still worked by hand. “Everyone can see that AI is changing the threat landscape. It might also hold the answer, but most people are focused on automating the wrong bits,” Fischer said when Hadrian raised a $40 million Series B in October 2026. The company now has about 90 people, and 10 to 15% of them come from ethical hacking.