Week 9 covered "where data is stored, how it's processed, who sees what, and how it flows in real-time." Memorizing individual services alone won't pass SAP exams. Exams always ask "under these constraints (cost, real-time, operational burden, portability, permission granularity), what is optimal?" and only one of two similar-looking services satisfies all conditions. Today we consolidate the week's pieces into one unified architecture picture and sharpen boundary-drawing through scenario drills.