In this interview, Iria Nicholas, Technical Director of Process Engineering at SLR Consulting, explores the key considerations involved in selecting the most suitable feedstock for an anaerobic digestion (AD) plant. The discussion examines how local feedstock availability, economic viability, and environmental performance all play a role in determining the optimal feedstock mix and plant design. It also highlights the importance of evaluating parameters such as biogas potential, dry matter content, and nutrient balance using reliable and representative data. Finally, the interview addresses common challenges, including feedstock contamination, evolving environmental regulations, and digestate management, emphasizing that a well-balanced feedstock strategy is essential for efficient and sustainable plant operation.