I'm applying for some big companies and the areas I seem to be getting burned on is problems involving limited memory, disk-space or throughput. These large companies process GBs of data every second (or more), and they need efficient ways of managing all that data. I have no experience with this as none of the projects I have worked on have grown that large.

Is there a good place to learn about or practice these sorts of problems? Most of the practice-problem sites I've encountered only have problems where you have to solve something efficiently (usually involving prime numbers) but none of them limit your resources.