Initially, before implementing the domain model, the dependency and configuration classes need to specified. The following Maven starter dependency  needs to be included:

<dependencies>
   <dependency>
      <groupId>org.springframework.boot</groupId>
      <artifactId>spring-boot-starter-data-mongodb-reactive</artifactId>
   </dependency>
   ...
   <dependency>
      <groupId>de.flapdoodle.embed</groupId>
      <artifactId>de.flapdoodle.embed.mongo</artifactId>
   </dependency>
</dependencies>

The preceding entries import all the dependencies of the MongoDB Reactive stack and an embedded MongoDB, which can be used to store documents.