It’s really not that hard if you have the equipment to support it. Most of it is planning/logistics.
After some experience you kind of know how many people something will feed. Example- I used to figure a 400 count bag of clams was good for 10 people at a clambake. 5# box of shrimp the same for shrimp cocktail. Had similar for salads, corn, sausage, chowder, etc.
July 22 was the date nearly 40 years ago. Had a clambake for 50-60 on one lake an hour away. Same time I had another bake for 300 on another lake.
Later that afternoon I had another bake for 6-700 at a park just down the street from our base of operations bar/restaurant/sub shop.
I also had a Class Reunion back at the bar for about 200 that night.
It was a long day. I had to ride my motorcycle between locations because every available pickup (including my own and my boss’s) were needed for “work” to get product/beer, etc where it belonged.
I even had an old fashioned “tap” truck at the large bake for dispensing draft beer. (The truck was “free” if I had the distributor put 25 halves in it


).
I was tired, but had a lot of great help.