1. Cut a process which was taking 20 mins down to 40 seconds — moral of the story is: building systems which allow you to see the system work in real-time and get an intuitive sense for how long things take is more effective than poring over SQL logs trying to figure out what on earth’s going on in retrospect.

  2. Loving Django’s prefetch/select_related — that, along with a few small changes, reduced a task which was taking > 500,000 queries to 4558