Push some big numbers through your system and look for bugs
Why does this matter? Okay, let’s say you have a JSON message where you pass around the unique ID of some object in your system. Let’s further say that your system “mints” IDs out of a 64 bit number space, and it spreads them around, so large numbers can turn up every now and then. What happens when you finally get an object ID with a value of 1152921504606846976 and put it into a message?