One of my jobs is as a cook/butcher, but occasionally I'm asked to work our coffee bar. In the late afternoon, between the shift change for our baristas there is a small rush. During these times, I have been asked to work our coffee bar, if needed. Originally, I ended up in the position because I was the only person with any experience using an espresso machine. Now, I offer my services to practice and work on the commercial machine and in a production environment.
Since I've started doing this, I've been asked by a few friends about the differences between working at home one a home or semi-commercial machine and in a shop. Of course, before I can really say much, I always give the caveat that I'm not a barista, I just occasionally work a small rush for half an hour or so which means my perspective is skewed.
That said, I've noticed significant differences in how I pull a shot and dial in coffee at the shop versus at home, just as I cook differently in a professional environment. First off, the machine we use at the shop steams much faster than any other espresso machine I've used. It takes about 20-25 seconds to steam milk for a latte. It certainly took some getting used to that speed. Additionally, we have a three group machine and often need to use all three groups at once. Concentrating on pulling multiple shots at the same time while preparing milk, keeping flavorings (if any) ordered and making sure to get to go orders ready in appropriate serving-ware.
Beyond keeping track of multiple orders and using a faster machine, there are differences in how I actually pull the shot. At home, I weight each dose out, grind and pull a shot. At the shop, we use a Mazzer Robur with an accurate timer (although, not as accurate as weighing each dose), so there is no need to weigh out each shot. Grind and go, a huge time saver. Also, at home, I am far more meticulous about cleanliness trying to avoid getting coffee grounds anywhere. At the shop, I work cleanly, but getting some coffee grounds on the counter isn't a big of a deal, in fact in some places it is unavoidable.
Overall, the goal at the shop and at home is the best cup of coffee possible, but the ends are different. At home, I have all the time in the world and can work exactly how I want to, but try not to waste too much coffee dialing in the coffee. In contrast, at the shop we dial in the coffee first thing and adjust throughout the day while we focus on pulling multiple shots quickly
while retaining quality.