Users on GitHub can watch repositories to receive notifications about project activity. This introduces a new type of passive project membership. In this paper, we investigate the behavior of watchers and their contribution to the projects they watch. We find that a subset of project watchers begin contributing to the project and those contributors account for a significant percentage of contributors on the project. As contributors, watchers are more confident and contribute over a longer period of time in a more varied way than other contributors. This is likely attributable to the knowledge gained through project notifications.

Software systems have not only become larger over time, but the amount of technical contributors and dependencies have also increased. With these expansions also comes the increasing risk of introducing a software failure into a pre-existing system. Software failures are a multi-billion dollar problem in the industry today and while integration and other forms of testing are helping to ensure a minimal number of failures, research to understand full impacts of code changes and their social implications is still a major concern. This paper describes how analysis of code changes and the technical relationships they infer can be used to detect pairs of developers whose technical dependencies may induce software failures. These developer pairs may also be used to predict future software failures as well as provide recommendations to contributors to solve these failures caused by source code changes.