Ably is developing a comprehensive guide to building a fully-featured, scalable chat application, addressing the complexities and challenges that developers face, such as authentication, message storage, and user roles. Their approach leverages a tech stack that includes React for the frontend, Azure Functions for the backend, CosmosDB for data storage, and Auth0 for authentication. The guide aims to help developers integrate core chat functionalities, like chat rooms and message editing, as well as advanced features such as commands, notifications, and media sharing, ensuring that the chat application can handle large-scale user interactions. Through a series of blog posts, Ably plans to demonstrate best practices and provide code on GitHub, inviting feedback from the community to ensure the guide remains beneficial and relevant for those building chat applications.