Lundgren joined IKEA in 1953 as a technical draughtsman. He worked closely with IKEA founder Ingvar Kamprad to develop the simple, functional furniture designs for which IKEA is now known worldwide. He is notably the author of the famous Billy shelf, launched in 1979 and sold millions of units worldwide. In addition to his work at IKEA, Lundgren has also worked as a freelance designer for other companies, and has been involved in the creation of several architectural projects in Sweden. In recognition of his contributions to industrial design, he has received numerous awards and distinctions over the course of his career.