How you know you hired a good deck builder
They are licensed and insured and have experience in construction and wood working. They know how to read blueprints, they know how cut and measure materials. They should be able to fix any problems or notice and problems with a faulty deck. They are in touch with you through every step, including when materials will be there, when they will start site prep, and when they will start building the deck. The business should make it a overall great experience for you.