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+```mermaid
+sequenceDiagram
+    participant User
+    participant PaymentService
+    participant DomainModel
+    participant Repository
+
+    User->>PaymentService: 결제 요청
+    PaymentService->>DomainModel: 결제 처리
+    DomainModel->>Repository: 데이터 저장
+    Repository-->>DomainModel: 저장 성공
+    DomainModel-->>PaymentService: 처리 완료
+    PaymentService-->>User: 결제 성공
+
+    alt 외부 실패
+        PaymentService-->>User: 결제 실패
+    end
+
+    alt DB 실패
+        DomainModel->>Repository: 데이터 저장 실패
+        Repository-->>DomainModel: 저장 실패
+        DomainModel-->>PaymentService: 롤백
+        PaymentService-->>User: 결제 실패
+    end
+```
\ No newline at end of file