Arne Bartelt focused on backend development and database management within the nextcloud/deck repository, addressing a MySQL-specific issue related to board member deletion. Using PHP and SQL, Arne refactored the deletion logic into a two-step process that first collects relevant assignment IDs before executing the deletion, ensuring compatibility across MySQL versions and adherence to best practices for foreign-key constraints. This approach improved the reliability and maintainability of the board member management feature, reducing user-facing errors and support needs. The work demonstrated careful attention to data integrity and operational robustness, resulting in a clear, low-risk update to the project’s codebase.