Mathematics in Action at the Center of Technological Research and Development. This book discusses the role of mathematics in numerous technological applications. The selected applications are predominantly modern and provide students with insight into mathematics in action. The book is primarily designed for students in intermediate and advanced years of study, as a certain level of mathematical maturity is required. The text is also suitable for aspiring high school teachers. However, only basic knowledge of linear algebra, probability theory, Euclidean geometry, and functions of several variables is assumed. The book covers many other topics as well, but all necessary mathematical tools (group theory, finite fields, etc.) are introduced in an elementary way and integrated into the presentation of the respective topic.