An Assembly developer works with assembly language, a low-level programming language specific to a computer architecture. They write, test, and debug assembly code, translating high-level instructions into machine language to directly manipulate hardware, memory, or processor operations. This could involve creating software like operating systems, firmware, or embedded systems. They may also optimize code for speed or size, in contexts where resource usage is critical. Assembly developers need a deep understanding of computer architecture, memory management, and operating systems. Their work is complex and meticulous, needing precision as mistakes can lead to system-wide issues.