In the last couple of chapters, we gained a firm grasp of the fundamentals of the Kotlin programming language by implementing the classic game, Tetris. In Chapter 3, Implementing Tetris Logic and Functionality, we finished the development of the game by implementing its application logic. We created programmatic models for blocks, shapes, frames, and the application as a whole, via an app model class. In addition, we learned how to create custom views by implementing Tetris view—a view that the user of the application interacted with to play the game.
We will hone our Kotlin development skills further by developing a simple messenger application for the Android platform. In the process of implementing the Android application, we will first develop a RESTful API that will provide web content to the application behind the scenes. The application programming interface will be built with Spring Boot 2.0. After developing the application programming interface, we will deploy it to a remote server. Over the course of this chapter, you will learn about the following topics:
- Basic system design
- Modeling system behavior with state diagrams
- Database design fundamentals
- Modeling a database with entity relationship (E-R) diagrams
- Building backend microservices with Spring Boot 2.0
- Working with PostgreSQL
- Dependency management with Maven
- Amazon Web Services (AWS)
Without further ado, let's dive into this chapter by designing the messenger application programming interface.