Abstract Selective laser melting (SLM) promises not only geometric freedom, but is envisioned to allow tailored microstructures as well. While the possibility to be able to build chosen microstructures in certain areas of a part is often seen as a feature, the local change in microstructure due to a changing geometry is just as often seen as a bug. Since the formation of microstructure depends on local temperature gradient and solidification rate, simulations must be able to predict both quantities to reflect experimental results. We use thermomechanical simulations on the part scale and thermofluidic simulations on the powder scale to show the influence of geometry on the temperature gradient and solidification rate. Being able to predict these quantities the user can actively decide between feature and bug and adjust process parameters accordingly.