IT controlling is established as an instrument for managing information technology. The job description of the IT controller has changed only moderately over a longer period of time. It was primarily associated with IT budgeting, IT portfolio management, IT cost planning, accounting and controlling. However, digitization has brought movement in objectives, content, and methods. New topics such as digital strategy management, cloud controlling, data science and others are under discussion. The task profile is changing away from pure IT cost analysis to management of the digitization strategy with a focus on strategic IT portfolio management. Some voices are already talking about "smart controlling" or "digital controlling". This book is a translation of an original German edition. The translation was done with the help of artificial intelligence (machine translation by the service DeepL.com). A subsequent human revision was done primarily in terms of content, so that the book will read stylistically differently from a conventional translation. Prof. Dr. Andreas Gadatsch holds the Chair of Business Administration, in particular Business Information Systems and is Director of the Institute of Management at Bonn-Rhein-Sieg University of Applied Sciences. He heads the master's program in Innovation and Information Management (MSc) as well as the Data Innovation Lab. .