While evaluating an API to use I stumbled onto the unit tests. A lot of tests were named <sometest>StressTest. This struck me. We write a lot of tests to find out if things work the way we expect in the pattern: setup / do something / check outcome. While this is good, for some types of tests it is better to take some stress factor into account. That way you are more likely to find problems, while still testing for the obvious.