How developer coreness influences the patch-review process: A mixed-method study

Abstract

The code integration process is critical for any distributed, large-scale open-source software (OSS) project. It serves as an implicit or explicit quality control gate and is inherently of a socio-technical nature in that the bare technical act of merging new code contributions is preceded by (oftentimes engaged) discussions and reviews. Given the reasonable and widely accepted assumption that professional experience and seniority lead to higher social credit in communities, more experienced developers are expected to get favored in this process, manifesting in higher probabilities of receiving feedback on contributions, or getting contributions accepted. We conjecture that exceptions to this pattern may indicate procedural issues and examine this hypothesis through a mixed-method study. To this end, we use developer coreness, a continuous proxy measure of experience that measures how important and connected a developer is within a project. We then study code integration processes of 16 popular OSS projects, employing a new methodology to measure the impact of developer coreness on these processes. This allows us to identify process-deviant projects, which we investigate qualitatively to determine whether unexpected observations indicate underlying procedural issues. Our findings show that developers with higher coreness values have a higher probability of getting code contributions accepted and, in many cases, of receiving feedback. Notably, projects identified as process-deviant often exhibit signs of procedural deficiencies, highlighting the practical utility of our methodological framework.