Atomic-scale understanding of heterogeneous electrocatalysis has matured enormously over the last years. Alongside numerous experimental developments, this progress is largely owed to simultaneous advances in first-principles simulations of the electrified solid/liquid interface. Extensive methodological work has, e.g., been devoted to developing theoretical models for interfacial charge transfer, providing appropriate descriptions of the aqueous solvent, and capturing relevant effects from electrolyte ions. Among these challenges, a topic which currently receives particular attention concerns effects of the local interfacial field that arises due to capacitive charging of the electrical double layer (cf. e.g., refs 6-9). Open questions on this front include, for example, how such effects manifest during realistic working conditions? But also, to what extent can they influence reaction mechanisms and, hence, catalytic performance?