This kind of work requires experts. There is no substitute for in-depth deck-building expertise. There is a great difference between a composite deck that was built by a master carpenter and one built by an amateur or inexperienced builder. The former must go through years of instruction, training, and apprenticeship before they earn their credentials. The latter can consist of any old day laborer off the street. You want to work with a deck building company that is staffed with master carpenters. Your kids will play on that deck. You want to be sure it is put together soundly by people who know what they are doing.