Tillemann is the Chief Policy Officer of Haun Ventures where he helps build policy architecture to support the next generation of the internet. Previously, Tillemann was a partner and Global Head of Policy for the web3 team at Andreessen Horowitz (a16z). Tillemann served as Senior Advisor to two secretaries of state, leading a team of experts that built 20 major initiatives in 55 countries. 

He joined the State Department in 2009 as Hillary Clinton's speechwriter and spent four years on the professional staff of the Senate Foreign Relations Committee supporting Joe Biden, Tony Blinken, Barack Obama, and John Kerry. Tillemann also served as the Executive Director of the Digital Impact and Governance Initiative at New America, where he led programs to address social impact, finance, and governance challenges worldwide and authored extensive research on how to harness frontier technologies to strengthen democratic institutions. 

He has led a dozen successful efforts to use open source and decentralized technology to address public corruption, increase government efficiency, and promote private sector accountability, and helped to deploy the world's first decentralized land registry and managed the development of groundbreaking open source platforms for city, state, and federal agencies in the U.S. and worldwide. He has served as a member of the World Economic Forum’s Council for the Fourth Industrial Revolution, the United Nations World Food Program Innovation Advisory Council, the Lantos Foundation Board of Trustees, and as Chairman of the Global Blockchain Business Council. 

Tillemann is a co-holder of four patents. He received his B.A. magna cum laude from Yale University and holds a Ph.D. with distinction from the School for Advanced International Studies at Johns Hopkins University.