Design an in-memory database with TTL and backups

Design an in-memory key-value service that supports writes, reads, prefix scans, expiration, and point-in-time snapshots. Time is represented by an integer t, and timestamps are guaranteed to be nondecreasing across the input. You are given operations, a list of operations in the order they should be processed. Each operation is a list whose first element is one of the command names below. Process them in order and return a list containing one item for every operation that…