This article discusses creating a user profile service using Kotlin, Spring Boot, and Couchbase. The author starts by converting a Java application to Kotlin and then creates a sample application to demonstrate the combination of these technologies. They explain how to map entities to Couchbase documents using annotations such as `@Document`, `@Id`, and `@Field`. They also discuss how to use Spring Data keywords, such as `@Repository` and `@Query`, to query the database. Additionally, they provide an example of a service that forwards requests to a repository and includes ad-hoc queries for testing purposes. The article concludes with instructions on how to write integration tests using Kotlin and Maven dependencies.