excellent understanding and knowledge of processor architecture, specifically ARM and its vector unit NEON. Additional Intel SSE or PowerPC AltiVec is also very helpful. Being able to use processor micro-architecture to write and deliver fast routines is an essential attribute.
Neon, they remind us, is the brand name for the ARMv7 Cortex, the next-generation of the processor Apple uses in the current iPhone and iPod touch.
What's not yet clear is whether Apple will tap the multi-core potential of the ARMv7 Cortex to really shift multimedia performance into the mobile stratosphere. However, another tantalizing glimpse into the iPhone's potential future is revealed in a second job listing, this one for an engineer with:
Experience developing embedded image and video processing solutions. Experience developing embedded image and video analysis solutions. Experience working on real-time media and networking applications (WiFi and cellular networks).