When doing a catering job on Shabbos, regarding hachanah can the goyim bring out all the equipment outside once the simcha is over on shabbos in order for it to be ready to be loaded once shabbos ends?
There are two issues with having the gentile’s bring out all the equipment for after Shabbos. If they are doing because they are told to, or because they know that you want to get out of there as soon as possible after Shabbos. Then they are doing for you, and not just because this is their job. Secondly, even if they are doing for themselves, other people seeing this will think that you hired them to do this, additionally doing it is public is a disgrace for Shabbos and considered zilzul Shabbos.
O:CH 244, The Sanctity of Shabbos pg. 73