A Creative Engineering Firm that Understands Architecture. Mattson Macdonald Young is a structural engineering firm established in 1983 by Wesley Mattson and David Macdonald. The firm provides engineering services to all types and sizes of clients. We have served as the structural engineer of record for projects ranging in size from multi million dollar developments to residential porch additions. The firm’s size and philosophy allows this type of flexibility and diversity, and we often find new ways that we are able to help our clients with our engineering and construction expertise.