Intrigued by the possibility to alter enzymes at will, I embarked on a PhD program in biocatalysis. My first lesson in generating enzymes for industrial application taught me how to find a suitable starting point. In this work, I characterized a fungal monooxygenase that turned out to feature a number of useful characteristics. Flanked by a structural characterisation in collaboration with a group at the University of Pavia that hosted me as a guest researcher for part of this project, I demonstrated that this enzyme is more thermostable than most characterized homologs, and has a very broad substrate spectrum. With promiscuity being a frequently sought-for feature for a biocatalyst, this work was also an opportunity to first delve into the realm of analytical chemistry. Accordingly, I devised a method for rapid identification of substrate scopes based on mixed bioconversion assays followed by chromatographic separation and analysis by mass spectrometry. In combination with enzyme kinetic measurements, I revealed a particularly striking activity of this enzyme with pharmaceutically relevant polycyclic ketones such as steroids.