Hiring an assembly language programming developer is crucial for tasks requiring direct hardware manipulation, real-time constraints, or systems-level programming. They can write efficient, high-speed code for applications where performance is critical. Such developers also excel in understanding the inner workings of a machine, enabling them to optimize code, manage system resources, and troubleshoot more effectively. Their knowledge proves invaluable in sectors like embedded systems, game development, system drivers, and more. Thus, for projects demanding high performance, low-level system access, or custom instructions, an assembly language programmer is an asset.