Ever since the emergence of integrated circuits, incredible efforts invested by the scientific community and semiconductor industry have led to shrinkage of individual transistors from a few micron to the 10nm scale. This tremendous downsizing will finally meet a fundamental barrier since quantum effects start to arise for structure sizes that approach the de Broglie wavelength of the electron. Going beyond conventional Silicon-based electronics, spin transistors have the potential to overcome these limitations. Nevertheless, to perform spintronics at a reliable level requires a thorough understanding of underlying dynamics occurring at time scales of tens of femtoseconds. In my project, we focus on these ultrafast processes in many different systems to gain deeper understanding of spintronic´s nature.