Arrive on time. It's important that you are on-time for an interview. By doing so, you're showing that you are mindful and respectful of the interviewer's time. Arriving late can negatively impact your chances of landing the job, as it shows a sense of apathy and indifference.
There are two types of lever machines; manual piston and spring piston design. With the manual piston, the operator directly pushes the water through the grounds. In the spring piston design, the operator works to tension a spring, which then delivers the pressure for the espresso (usually 8 to 10 bar; 116 to 145 psi). Steam-driven A steam coffee machine
Ultimately, most baristas agree that the best grind size is the one that results in a shot that pulls in 23 to 29 seconds and (Very important!) tastes great. To grind coffee beans for espresso, fill the hopper and activate the grinder for about 15 to 20 seconds.