During the week, I work as a barista! I love making espresso-based coffee drinks!
I love coffee!  Was it hard to learn?
It was a little tricky learning how to operate the espresso machine! It can be quite finicky! 
When did the profession of Baristas come about?
I'm pretty sure it's an old profession. The word barista is an Italian word that translates to bartender. Most Italian baristas serve hot drinks, cold alcoholic drinks and snacks. I'm not so sure when the term came to the US.
Interesting, I didn't know that?  Is it customary to tip a barista?
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,
Barista
A barista (; ; from the Italian for "bartender") is a person, usually a coffeehouse employee, who prepares and serves espresso-based coffee drinks.
Etymology and inflection.
The word "barista" comes from Italian, where it means a male or female "bartender" who typically works behind a counter, serving hot drinks (such as espresso), cold alcoholic and non-alcoholic beverages, and snacks. The native plural in English is "baristas", while in Italian the plural