This document discusses Symfony Flex, a tool for automating the installation and configuration of Symfony applications. It covers starting new Symfony projects, the simplified project structure in Symfony 4, and common practices like using environment variables and the webpack asset manager. Symfony Flex installs bundles and their dependencies, allows configuring applications via recipes, and supports contributing new recipes to help others install and configure packages. The presentation was given by Denis-Florin Rendler to explain Symfony Flex and how it helps compose Symfony applications.