Dive deep into the power of Go interfaces in this 53-minute conference talk. Explore how interfaces enable flexible, reusable, and testable application and library development. Discover the unique approach Go takes with small, implicitly implemented interfaces, and learn how this paradigm shift impacts program design. Through hands-on examples, gain a comprehensive understanding of interface benefits, definition, implementation, and usage. Apply interface concepts to enhance code reusability and testability, and explore best practices for maximizing their value. Cover topics including the stringer interface, small interfaces, IO operations, testing, composition, type assertions, and the empty interface. Gain insights into working with Go, generics, and object-oriented principles in Go programming.