Barista

Wikipedia - "A barista ... is a person, usually a coffeehouse employee, who prepares and serves espresso-based coffee drinks. ... Baristas generally operate a commercial espresso machine, and their role is preparing and pulling the shot; the degree to which this is automated or done manually varies significantly, ranging from push-button operation to an involved manual process. Espresso is a notoriously finicky beverage and good manual espresso making is considered a skilled task. Further, preparation of other beverages, particularly milk-based drinks such as cappuccinos and lattes, but also non-espresso coffee such as drip or press pot, requires additional work and skill for effective frothing, pouring and most often latte art. The barista usually has been trained to operate the machine and to prepare the coffee based on the guidelines of the roaster or shop owner, while more experienced baristas may have discretion to vary preparation or experiment."
Wikipdia
Barista
Inside The Barista Class
YouTube: il barista, How to Make a Latte Art Heart | Perfect Coffee, Arte Latte - Especialistas del Café S.A.

2010 September: Espresso, April: The History of Coffee and How It Transformed Our World, 2013 May: Coffeehouse