Explore the intricacies of building RESTful APIs with Symfony in this comprehensive 50-minute conference talk from PHP UK. Delve into the theoretical foundations of creating a "good" RESTful API before diving into practical code examples. Learn to leverage powerful tools such as FOSRestBundle for efficiency, JMS serializer for advanced features, and the HATEOAS project to achieve the highest level of the Richardson maturity model. Discover how Guzzle can streamline communication between applications in a Service-Oriented Architecture. Gain insights into key concepts including HTTP methods, content negotiation, request body conversion, validation, error handling, and authentication. Demystify the technologies in the "REST" ecosystem and walk away with the knowledge to create robust, efficient APIs using Symfony.