In general, no. The head chef is overall in charge. It’s his kitchen and his operations. In the case of a larger establishment where the head chef is an Executive Chef, he might have a Chef de Cuisine (or some other title) to handle the day to day operations. But there is one person at the top. If there is a banquet operation he might hire a banquet chef. If the place is huge, he might also have a pastry chef that just handles all the baking. But in all these cases, there is one person in charge. Staffs? Sure, there might be a banquet staff, and “day shift” and a “night shift” for kitchen and front of house, and sometime these are flexible and sometimes not. At the country club we had two guys who only were able to work mornings and lunch (they both had other jobs that they worked at night), so you could say they were only hired for one of the shifts, but in general the kitchen staff could flex from 6:00AM to Closing after a banquet. We ran a bigger line in the evening so some guys were pretty much only evenings. Some of the wait staff got bounced around pretty good, but others (those with kids, mostly) were strictly evening shifts. I don’t use them. It’s far cheaper, and you have more control over ingredients if you shop and cook meals from scratch yourself. It’s just not that difficult. It’s just a matter of practice, and resolve to learn a basic life skill.
Well for starters people in the US tend to eat earlier than the people in Europe therefore it’s normal for domestic passengers to have had something to eat by 9pm. In US International Airports, the requirements for concessions remaining open are a little different and more customizable to the flight departure times, cancellations or delays. The stance that most US airports take on concessions is that you keep the larger restaurants open until 30 minutes prior to last flight and then keep something open with grab and go food such as a travel convenience store open in case there are delays or cancellations. You cannot please everyone and the amount of passengers in terminals after 9pm dwindles down tremendously therefore airports have to consider the financial well being of their concession partners at all times. Also, in Europe the focus is mostly on Duty Free and Retail shops but here in the US it’s reverse, more Food and Beverage is prevalent throughout all US airports. The economy in certain areas drives a lot of minimum wage jobs because the employer must meet his market price demand. You just need some person and a vehicle to deliver the food. In fact, if you live in the neighborhood of a commercial/ office complex then even a bicycle will do as a vehicle.