This chapter will help the reader get started in developing RESTful APIs using Spring Boot 2.0 with the Kotlin programming language. It will enable experts, as well as beginners, to Spring Boot web application development, to understand the concepts behind a RESTful API written entirely in Kotlin. It will explain these concepts by walking the reader through the process of developing a RESTful API that enables users to list movies, get movie details, rate movies, and so on. This RESTful API will use an embedded MongoDB platform for persistence, Spring Data MongoDB Reactive for the model, a repository, and Spring WebFlux for controllers.

The following topics will be covered in this chapter:

• Using Spring Data MongoDB for persistence
• Using Spring WebFlux for the controller
• Using Spring Security for basic authorization
• Demonstrating Moviee