Style guides and component libraries are the new trend in front-end development. Everyone is into “Atomic Design” and “Modular CSS” nowadays. But how did we get to this “hype”, and why? What is a style guide, what is its value and where are the benefits of introducing one in a project? And are them useful only for the web, or can be employed by other platforms too? I’ll try to give an answer to all these questions in this presentation – directed to designers, web developers but also iOS/Android/Win developers – and I’ll show how our Mobile Web team in Badoo has developed his first style guide and how is using it to catch bugs and create a shared pattern library.