Electrification of endothermic reactions has the potential to provide a compact and flexible reactor concept, and at the same time, substantially reduce CO2 emissions relative to combustion-heated processes. Here, we show how integrated electrical heating using a wash-coated catalytic structure can resolve limiting thermal conductivity across the catalyst. The inherent uniform supply of heat enables engineering of catalytic efficiency to desired values by changing wash-coat thickness. Overall, the approach diminishes catalytic efficiency as a limiting design parameter. Instead, coat thickness will relate to catalyst lifetime, as very thin coats are more susceptible to deactivation. Characteristic time-scale analysis indicates heat transfer to be the least limiting mechanism, and reactor performance is instead governed by diffusion. Optimal performance based on fluid dynamic simulations favors internal diameters below 0.5 mm, and high linear gas velocities, toward alleviating mass transfer limitations. Integrated electrical heated steam methane reforming essentially inverts the order of reaction mechanisms compared to conventional reforming, challenging the constraints of current industrial practice.