shop assistant.
"bartender" refers to the person who was in charge of waiters in post stations, teahouses, wine shops, hotels and other places in ancient times (more common in early vernacular). It means second boss, which is a friendly title.
Shop assistants refer to waiters in the ancient service industry, who are mainly responsible for providing catering, accommodation, entertainment and other services for guests. They usually wear simple clothes, hold trays or flagons, and shuttle between guests' rooms to pour tea, deliver water and add rice for them.