Fostering innovation is essential to thrive and survive in the software industry. While the existing scientific literature widely assumes that companies can foster innovation by means of a centrally planned, top-down specified innovation process, little is known about the actual practices of innovative employees. This dissertation offers a distinct, practice-based perspective on digital innovation that emphasizes its bottom-up emerging character. Understanding digital innovation as a practice implies a paradigm shift from managing and controlling innovation processes to enabling and facilitating employee-driven innovation practices. The practice-based perspective is grounded in empirical insights from an in-depth qualitative case study at two software companies. By analyzing the important role of artifacts and social interaction in parallel, this dissertation contributes to a better understanding of digital innovation practices. Moreover, it presents tools to enable digital innovation practices by providing starting points to support employee-driven innovation with information systems.