Surly or ignorant.
Poorly paid menial worker.
Coffee shop attendant.
"Stop being such a barrista, and leave the poor man alone!" demanded Irene. "He can hardly even speak English".
"I ordered a semi skimmed latte, not full fat, you idiot!" bellowed Anton as he towered over the quaking form, then turning to Irene "Who are you calling a barrista anyway? I earn more in a day than this fool does in a month"