Interface engineering is a research field and methodological approach concerned with the design, control, and modification of interfaces between distinct phases or materials. Within the domain of nuclear science and technology, it specifically investigates the critical interfaces between components such as nuclear fuel, cladding, coolants, structural materials, or plasma and containment surfaces. Its primary objective is to precisely tailor interfacial structure, chemistry, and properties to optimize material performance, mass/energy transport, and overall system efficiency, safety, and durability under extreme operating conditions.