Contentful, an API-first CMS, can be integrated with Hasura using GraphQL and Remote Joins to create applications with rich content, such as a blog CMS or a playlist app. By using Hasura's Remote Joins feature, which is in preview, developers can join data across tables and remote sources, like combining user data from Hasura with blog post data from Contentful. The process involves creating content types in Contentful, such as a Blog Post with fields like title and content, and connecting this data to Hasura’s users table via the author field. To facilitate querying, Contentful is added as a Remote Schema in Hasura, requiring a GraphQL Content API Endpoint and an access token for authorization. A remote relationship is established from the users table to the Contentful blogPostCollection, allowing for queries that retrieve only the relevant blogs authored by specific users, thus demonstrating the seamless integration of remote content into a cohesive application.