Enzymes are important biocatalysts with many applications in medicine, food technology and the chemical industry. To further expand their reaction scope and to meet the demands of industrial processes, the enzymes’ properties are routinely optimised by protein engineering. Due to a rapidly increasing number of protein sequences and structures and powerful computational tools, rational approaches are nowadays complementing random approaches. However, in most cases combined approaches prove to be most successful. Dr Kerstin Steiner, Project Manager and Senior Researcher at the Austrian Center of Industrial Biotechnolgy (ACIB) submits a white paper on enzyme engineering for industrial biocatalysis.