Do baristas roast coffee beans?

Yes, but it is now considered improper for baristas to do so. They are now trained to simply operate the machines brewers use to brew coffee. It's worth noting that this same preparation method also applies when someone prepares espresso or cappuccino at home - there's no roasting involved in these cases either. There is also one machine on the market called a "freestanding roaster" where you can add green beans and roast them yourself while having the convenience of preparing coffee instantly by just flipping a switch on the front of the machine!