This document contains slides from a presentation by Luca Del Puppo about building GraphQL servers using Fastify and Mercurius. The presentation introduces GraphQL and its advantages over REST APIs. It then discusses why Mercurius is a good choice for building GraphQL servers on Fastify and outlines some features it provides out of the box. The presentation concludes by providing resources for learning more about Fastify, Mercurius and building GraphQL servers.