Introduction and philosophy of doing optimization.

Hardware architecture that you should know for understanding why optimization strategies work.

Basic profiling methods and tools you should know when you spot CPU bottleneck.

Basic profiling methods and tools you should know when you spot GPU bottleneck.

Some more details when you want to wrok on shader optimization.

More details about rendering pipeline: topics like deferred rendering, tiled rendering,  lighting,  shadow, etc.

Loading assets can also be an issue. Let's look at textures, audio files, models, and all of those stuff.

I know you look for help because you have a task to optimize on mobile devices :) 

More details about memory optimization and profiling.