Design a Multi-Level In-Memory Cloud Storage Service

Approach Overview The problem requires building an in-memory cloud storage service where data is organized in stages, supports prefix-based ranking, enforces per-user capacity limits, allows merging data across partitions or users, and provides conflict-aware backup and restore. The precise state transition rules are not fully specified up front, so the implementation must surface errors whenever an operation is attempted in an invalid state. Since every approach must…