Hiring a Common Lisp developer can be beneficial due to their expertise in this multi-paradigm programming language, known for its flexibility and efficiency. They can create powerful, high-performance applications with unique features, thanks to Lisp's interactive development and dynamic typing. Lisp developers are also skilled problem solvers, often being able to find creative solutions due to the language's expressiveness. Furthermore, Lisp's macro system allows developers to effectively customize the language to fit specific needs, increasing productivity and code clarity. Thus, a Lisp developer can bring versatility, innovation, and efficiency to your project.