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
A steam-driven unit operates by forcing water through the coffee by using steam or steam pressure. The first espresso machines were steam types, produced when a common boiler was piped to four group heads so that multiple types of coffee could be made at the same time.