The first job listing shows that Apple wants an individual with experience with ARM processors and NEON unit vector to join the team.
The successful candidate will have 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.
The second job listing is looking for an individual to help Apple deliver cutting edge video embedding technology.. The most interesting bit is where the job description specifically calls for
Experience working on real-time media and networking applications (WiFi and cellular networks).