Pleased to announce my first @AntithesisHQ project: a property testing webinar! In property testing, instead of checking "this input to the function has this output", we check "given a million random inputs, all the outputs have this property". PBT has been around for a quarter century now and is fairly well known in functional programming and distributed system circles. Which is why we're gonna do something very experimental and target a community that almost never uses PBT: web developers. See, there's a thousand PBT tutorials out there, and they all use examples like "reversing a list twice returns the original list" and "add(x, y) should return the same result as add(y, x)". These are stateless properties on the code's functions, where we randomize inputs to a fixed test sequence. People have a hard time finding useful stateless properties in their systems. I've come to believe that most intuitive and useful business properties are instead stateful properties on what must always hold about the system's states. For example, "our total spend is always below our budget cap", or "two talks must never be scheduled for the same room and time", or "free users can't access premium features". We can property test these by randomizing the test sequence itself, to simulate a user doing whatever the heck they want, and testing that no matter what they do, our properties still hold. So, if you've ever had your data model get corrupted because you forgot to validate one update method, or seen a 500 when the user clicks `send` three times in a row, or gotten mad at SQL for not enforcing cross-table constraints, this webinar is for you. We'll be live on October 29. Sign up here: