Tim Sadler

Tim Sadler is a London-based technology entrepreneur and investor who co-founded and served as CEO of Tessian, an AI-powered email security company acquired by Proofpoint in December 2023. He subsequently served as Group Vice President and General Manager of the Tessian Group at Proofpoint from January 2024 to March 2026, and is currently a Sequoia Capital Scout and founder of a stealth-mode company. He is best known for building Tessian over more than a decade, raising $120 million in funding, and leading its integration into Proofpoint's product ecosystem.