Single source of truth One number described your product. It appeared in five places with five different values. The tool built to prevent exactly this had spent months making it worse. Five values for one fact The number was how many tools our server offers. A simple, countable fact. It is generated from the code itself, so there is no room for opinion. The generated truth said 122. Thirteen public pages said 126. The launch texts for Hacker News said 89. The marketing em...