jats:sec<jats:label />jats:pIn microelectronics, a device's functionality is shaped by its interfaces. While classical semiconductor research aims for the preparation of nearly ideal interfaces, the emerging paradigm is that new functionalities can arise from interfaces with less perfection. Memristive devices rely on the control of such less‐perfect interfaces. They are the building blocks for a new range of applications, including new memory and logic architectures and neuromorphic computing. Research on memristive systems and applications demands an interdisciplinary approach across disciplines, including solid‐state physics, electrochemistry, and biochemistry. Advanced metrology is the key for better understanding and finally a better control of such interfaces and novel device technologies. Herein, the authors highlight such recent advances in characterization and the understanding of electrochemical reactions on the (sub‐) nanoscale and the dynamics of the nanoparticles and clusters involved during operation of memristive devices acting as a model system. The authors focus particularly on in operando real‐time monitoring of the memristive switching effect by transmission electron microscopy and a novel plasmon‐enhanced spectroscopy method.</jats:p></jats:sec>