My first job after college was at Google. I had read the MapReduce paper and was so excited to run one, and luckily they did have a tutorial and I ended up runn

My first job after college was at Google. I had read the MapReduce paper and was so excited to run one, and luckily they did have a tutorial and I ended up running my first MapReduce within I think a couple weeks of joining, over Google's index of the internet at the time, which was really mind-blowing / exciting. I remember vaguely one task where i tried to join the index of the internet to some other dataset, which required joining across datacenters. The job ran with some warning. Then I got a friendly message from an SRE saying something like "it can cost thousands of dollars to run a join like that, so, no worries, just only do it if its something important." Of course, I wasn't doing anything important. I was just enjoying running MapReduce.