Built the backend for the Requirement page, where requests move through MES, AP, IT Server and OA review until the user verifies the result.

• Python FastAPI on an existing SQL Server table with SELECT and INSERT only: every change is a new snapshot row, and the current state is the newest row per request

• Writes take an sp_getapplock lock and check the expected revision, so a stale edit gets a 409, and idempotency keys stop double submits

• Workflow rules (allowed transitions, who may run each command, stage timestamps, task gates) live in a pure, tested module

• Attachments in MinIO, with the preview type decided from the file's bytes and uploads bound to the request by HMAC-signed tokens

• JWT identity, IT rights from the role table, and an encrypted connection string decrypted inside the container

• Project manager: planned the work, coordinated with other departments, and supported users after launch