A system performing under load is the holy grail of developers and stakeholders alike, but how do we know our software does actually perform under heavy stress? Come with me on a quick journey through the realms of load testing. I will present you eye-opening ideas about the different kinds of load testing there are and their purposes, how load can be modelled in programming, an extensible tool that can be instrumented to your needs, and most importantly, why –and how!– load test should be part of your TDD cycle.