Developer onboarding in GitHub: the role of prior social links and language experience

The team aspects of software engineering have been a subject of great interest since early work by Fred Brooks and others: how well do people work together in teams? why do people join teams? what happens if teams are distributed? Recently, the emergence of project ecosystems such as GitHub have created an entirely new, higher level of organization. GitHub supports numerous teams; they share a common technical platform (for work activities) and a common social platform (via following, commenting, etc). We explore the GitHub evidence for socialization as a precursor to joining a project, and how the technical factors of past experience and social factors of past connections to team members of a project affect productivity both initially and in the long run. We find developers preferentially join projects in GitHub where they have pre-existing relationships; furthermore, we find that the presence of past social connections combined with prior experience in languages dominant in the project leads to higher productivity both initially and cumulatively. Interestingly, we also find that stronger social connections are associated with slightly less productivity initially, but slightly more productivity in the long run.