In this World Development Report 2025 seminar series, Ulrich Harmes-Liedtke (Expert in Quality Infrastructure (QI) and Economic Development, Founding Partner at Mesopartner), Ann Ramkissoon (Doctoral candidate in development economics, University of Florence), and Christian Schoen (Co-Founder of Mesopartner) discuss "Quality Infrastructure Maturity and Trajectories: Experiences and Prospects of Advanced and Developing Economies" with chair Philip Grinsted, World Bank.