Version control branching allows an organization to parallelize its development efforts. Releasing a software system developed in this manner requires release managers, and other project stakeholders, to make decisions about how to integrate the branched work. This group decision-making process becomes very complex in the case of large-scale parallel development. To better understand the information needs of release managers in this context, we conducted an interview study at a large software company. Our analysis of the interviews provides a view into how release managers make integration decisions, organized around ten key factors. Based on these factors, we discuss specific information needs for release managers and how the needs can be met in future work.