The present Symposium is involved in the ERCOFTAC’s SIG 41 “Fluid-Structure Interaction” activities. Global challenges, such as climate change or reducing environmental impact, can be partially met through improved designs to increase energy efficiency and safety. From the engineering perspective, the major scientific challenge comes from the interaction between structures and the flow. Structural deformation may occur due to an external unsteady loading (FSI), through internal forces applied at internal members or on surface panels. Controlled deformation can be exploited for energy extraction from mean flows, to reduce noise or shape adaption for targeted aerodynamic properties. Deformation may lead to internal stresses and with cyclic loading, the potential for fatigue and failure. The dynamical response of structures and their interaction with the surrounding turbulence are intrinsically linked to critical flow processes that occur at points of separation linked to the structural design. The purpose of this in-person meeting is to discuss major science challenges associated with turbulent flow interfaces with deformable structures – from the theoretical, experimental and numerical perspective – and their link to design.