Who exactly are you dealing with and what is their relationship with the company? Various size companies are organized in different ways. You will want to know if you are talking to a salesperson, the owner of the company, or the guys that will actually be building the deck. Each position offers a unique perspective in how they deal with customers. It will be important that you are able to maintain responsive communication with this person throughout the different phases of the project. You will want to find out the name and phone number of the lead carpenter assigned to your project. Also you will want to know if your project will be subcontracted out to another builder. Subcontracting is not necessarily a bad practice as it can speed up production but it can result in employing less trained carpenters and increase the risk of miscommunication. Most deck building companies are relatively small, the more you know about how the company is organized the easier it will be for you to effectively communicate with the right people throughout your project.