You have paid a handful amount of money to the caterers, and all you have asked them to do is to deliver quality dishes. Before contacting the caterers, make sure you have visited their website, gone through all their brochures, considered every review. All of this, just to ensure that your guests are enjoying their food!
If the appetizers are greasy and oily, then the guests will be hesitant to try the dessert, after the meat section. If the desserts are not top-notch, then the ending is unsatisfactory.
Before the catering preparation starts, make sure the fruits, vegetables, meat, drinks are of premium quality. Consideration of food safety is a must, in a big event.