Hiring a GNU C developer brings expertise in one of the most powerful programming languages - C. They can develop efficient, high-performance software, as C allows close control over system hardware. Their knowledge of GNU tools enhances productivity, debugging, and code optimization. They can work on various platforms, including Unix/Linux, crucial for system-level programming. Their skills can be vital for projects involving embedded systems, game development, and other performance-critical applications. Their understanding of low-level programming also provides a solid foundation for learning other languages, making them versatile assets.