Coarse-grained approaches to customization allow the user to enable or disable groups of features at once, rather than individual features. While this may reduce the complexity of customization and encourage more users to customize, the research challenges of designing such approaches have not been fully explored. To address this limitation, we conducted an interview study with 14 professional software developers who use an integrated development environment that provides a role-based, coarse-grained approach to customization. We identify challenges of designing coarsegrained customization models, including issues of functionality partitioning, presentation, and individual differences. These findings highlight potentially critical design choices, and provide direction for future work. Author Keywords Role-based interface, adaptable and adaptive interfaces, customization, interview study. ACM Classification Keywords H.5.2 User Interfaces: Evaluation/methodology, graphical user interfac...