Clustering, Separation, and Connection: A Tale of Three Characteristics

In large and complex software development ecosystems, developers collaborate in multiple dimensions. How characteristics of such collaboration vary over time can offer insights about the dynamics of large scale software development. In this paper we have constructed networks of developers who co-comment on and co-change units of code, and analysed the patterns of variation of clustering, connection, and separation between such developers over time, using development data from a large open source system. Though clustering, connection, and separation essentially represent facets of the same collaboration activities, we found them exhibiting distinct time-varying characteristics. The variation of clustering indicate that developers congregate more closely towards the beginning of the project when the architecture of the system is not yet stable and they need to reach out to one another to fulfil their collective responsibilities. However, separation between developers shows a quick rise and then a saturation around a particular value. Developer connection continues rise throughout the observation period. Using time-series analysis, our results allow us to derive insights on the evolutionary trends in large scale software development and can inform the tuning of tools and process towards effective team assembly and governance.