Surprisingly, after decades of research, the exact mechanism of action (MoA) of many widely used antimalarials is still poorly understood in detail yet. Thereby, many show pleiotropic effects making the MoA of their parasite killing activity a mystery. Having said that, knowing the relevant molecular target is of great importance for structure optimisation of established drugs on the one hand, and it is crucial for the development of new promising drug candidates on the other hand. To gain a deeper understanding of the molecular and cellular effects of antimalarial compounds, and thereby push drug development, I am using various advanced biochemical and imaging techniques. In particular, I am using different genetically encoded biosensors to monitor cellular metabolites, such as ATP, in the malaria parasite Plasmodium falciparum. These sensors allow dynamic real-time live-cell measurements with subcellular resolution and thereby opening up a completely new perspective on drugs’ modes of action. Based on these findings, I found hints of the mechanism of action of the promising antimalarial structure class of arylmethylamino steroids, whose molecular targets are unknown so far. Going on from there, I want to follow up on those hints and further localize the targets to pave the way for further drug development.