백엔드

Outcome：Complete the task with 백엔드 (Backend)。 User context：결제할 때 백엔드는 재고를 확인하고, 대금을 청구하고, 주문 결과를 저장해요. Technical concept or control：백엔드 (Backend)。 Why it fits：신뢰할 수 있는 규칙, 공유 데이터, 통합, 서버가 필요한 작업은 백엔드에 두세요. Do not use it when：보안이나 돈과 관련해서 클라이언트 측 검증만 절대 믿지 마세요. Engineering requirements: Define inputs, outputs, contracts, and rules that must always hold. Set authorization and input checks. Define failures, timeouts, retries, one-time effects, data moves, and compatibility limits. Operations: Add useful signals and logs that hide sensitive data. Set capacity limits and write an operator guide. Test recovery and rollback. Acceptance criteria: Contract and failure-path tests pass. Data and authorization rules still hold during retries and partial failures. Check performance limits, monitoring, recovery, and rollback. Evidence and limits (evidence boundary)：하나의 공식 표준이 전체 용어를 통제하지 않음. 의미는 팀, 플랫폼 또는 프레임워크마다 달라질 수 있음. Unknowns to confirm: Where the code runs, data stores, traffic shape, consistency needs, and the security boundary. Also confirm the compatibility period, service goals, and rollback limits.