This talk gives an overview of the main Sirius features and shows how it can be used to create custom tooling for your own business or engineering domain. It takes the form of a customer-consultant role-playing game with a live demo of Sirius illustrating: How to use Sirius to create custom graphical modelers (diagram, table and tree editors) based on a given domain model (Ecore) The numerous customization mechanisms provided by Sirius to implement specific needs (conditional styles, filters, layers) The resulting Sirius modeling environment, ready to be delivered to end-users