Building a pub/sub service in Go

The text provides a comprehensive guide on implementing a publish-subscribe (pub/sub) messaging service in Go using Goroutines and channels for in-process communication. The pub/sub model allows publishers to send messages categorized into topics, which are then received by subscribers without either party knowing details about the other, enhancing system scalability and applicability in areas like streaming analytics. The guide outlines the creation of a Go package with a specific file structure and details the implementation of key components such as the message structure, subscriber and broker functionalities, and methods for subscribing, publishing, and unsubscribing to topics. It includes code snippets demonstrating how to manage message flow between publishers and subscribers, ensuring thread safety with mutex locks. The guide culminates with a practical example involving cryptocurrency price updates, illustrating the real-time operation of the pub/sub service. Additionally, the text briefly mentions the distinction between in-process and distributed pub/sub services, noting the latter's need for more robust fault tolerance mechanisms.