Diggit: Automated code review via software repository mining

We present Diggit, a tool to automatically generate code review comments, offering design guidance on prospective changes, based on insights gained from mining historical changes in source code repositories. We describe how the tool was built and tuned for use in practice as we integrated Diggit into the working processes of an industrial development team. We focus on the developer experience, the constraints that had to be met in adapting academic research to produce a tool that was useful to developers, and the effectiveness of the results in practice.