The S N Ar benchmark is a reaction between 2,4-difluoronitrobenzene and pyrrolidine to afford the desired products 3 with 4 and 5 as undesired side-products. Here, we aim to optimise the reaction in a virtual self-optimising flow setup, as shown in Figure . Formally, the optimisation problem can be stated as simultaneously maximising space time yield (ST Y ) and minimizing the E-factor (E). As noted in Equation , this is achieved by adjusting the residence time τ , inlet concentration of 1 C 1,i , equivalents of pyrrolidine n 2 , and reactor temperature, T .