The most important factors are engineering credentials, relevant project experience, and a track record of completing large, complex walls — not just landscape borders. For any wall over 4 feet tall, or on a sloped or saturated site, you need a contractor who understands geogrid reinforcement, soil mechanics, and drainage. Ask to see photos of similar projects. Ask about manufacturer certifications. In North Carolina, verify that your contractor holds an active general contractor license — ERWalls holds NC License #106946.