Soliman, MohamedKoziolek, AnneLamprecht, Anna-LenaThüm, ThomasBurger, Erik2025-02-142025-02-1420252944-7682https://dl.gi.de/handle/20.500.12116/45802Software developers commonly use mailing lists to communicate and discuss issues. Some of the emails discuss architectural design decisions (ADDs) to design the components of a system, or achieve quality attributes. In this paper, we explore (a) The types of ADDs in mailing lists, and their co-occurrences, and (b) Methods used by practitioners to discuss ADDs using both mailing lists and issue trackers (e.g. Jira). We applied qualitative methods, as well as deep learning classification to classify ADDs in mailing lists. Furthermore, we applied similarity algorithms to detect related ADDs between emails and issues. Our findings support empirically-grounded approaches to identify and classify ADDs in mailing lists and issue trackers for future system design.ensoftware architecturearchitecture knowledgedesign decisionssoftware repositories10.18420/se2025-042944-7682