Kanban board cross-project task architecture: 1. Backend controller needs 'all_projects' parameter support 2. Tasks must include project context for display 3. UI requires project selector dropdown with AJAX refresh 4. View layer needs to display project information on task cards 5. Comprehensive testing required including permissions and performance 6. Files involved: - /app/controllers/dashboard_controller.rb - /app/views/dashboard/kanban.html.erb - /app/assets/javascripts/kanban.js (or similar) - Multiple test files for different layers