This system isn't in production just yet, but should be shortly. We're parsing Dota2 replays and generating statistics and visualisation data from them, which can then be used by casters and analysts for tournaments, and players. The replay file format breaks the game down into 1 min chunks, which are the natural thing to iterate over.
Before someone comes along and says "this isn't big data!", I know. It's medium data at best. However, we are bound by CPU in a big way, so between throwing more cores at the problem and rewriting everything we can in C, we think we can reduce processing times to an acceptable point (currently about ~4 mins, hoping to hit <30s).