A promising option to store and transport clean energy are electrochemical fuels that can be converted to electricity on demand. Fuel cells, electrolysers and flow batteries are used for conversion to and from fuel and have advantages over batteries as storage capacity is cell size independent. Reactant and product transport set the maximum current density obtainable determined by the interplay between multiphase and opposing vapor and liquid flow. To understand this limit, a better way of controlling transport of reactant and products within electrodes is necessary. In particular, we need to (1) tune convection for distributing reactant concentration, (2) tailor the interplay between Knudsen and bulk diffusion, (3) tailor capillary forces to remove liquid products and (4) ensure fast reaction kinetics through reducing the reaction energy barrier. Electrode design is hence key, yet current architectures provide limited control over feature sizes, length scales and geometrical complexity, making the study of transport mechanisms tedious and controlled experiments difficult. We propose a radically new way of studying mass transport in electrodes via the direct conversion of multiscale computer designs into physical glassy carbon electrodes with desired surface functionality. We propose to (i) develop a photopolymer based AM process for tailored glassy carbon architectures with features ranging over multiple length scales, (ii) study the interplay between convective flow and diffusion throughout the electrode architecture, (ii) geometrically separate reactant and product transport, (iii) study and improve liquid product management and (iv) create catalytically active nitrogen doped carbon architectures potentially omitting the need for noble metal catalysts. ELECTRODE will improve our understanding of mass transport and arrive at a new toolbox for designing electrode architectures that may generate knowledge for next generation energy conversion and storage.