Siri de Vrijer currently serves as a Policy Advisor for the D66 delegation at the European Parliament, focusing on climate and environmental issues. Prior experience includes roles as a public affairs advisor at MVO Nederland and Public Matters, where expertise in strategic advising and program development was demonstrated. Siri has also contributed to the De Nationale DenkTank, analyzing barriers faced by specific groups in the labor market, and worked as a brand ambassador and teacher assistant early in the career. Educational achievements encompass a Master's degree in European History from Universiteit Leiden, Université Paris-1 Panthéon-Sorbonne, and the University of Oxford, alongside a Bachelor's degree in history from Leiden University.