The project idea is the most important part. You need to generate this idea very carefully and have to identify the facts behind your project. You need to keep in mind how this project could be effective on the market, how the users will accept your project, why they will use it, why they should choose your app instead of others, what features will make it different from other existing similar projects, and so on. After generating an idea, you need to create a draft in your mind of how will it look. Then you need to put it down on paper, design the workflow of the project, and then develop the project's code. Lastly, you need to test the project for its smoothness, check that it's bug/error free, and prepare it for the market.

In this chapter, we will create a small project that is like a social network. We will name it Packt Network. This project will have two parts. One is a server and one is a client, and both sides will be written in Kotlin. First of all, we create a Spring project where we will build our server and REST API. The data will be stored in a MySQL database, and we will handle the database using JDBC, JPA, and Hibernate. This data will be protected by the basic authentication of Spring Security. 

In our second project, we will create an Android application and handle the created REST APIs of the server. We will use Retrofit to handle the REST APIs and the network. Then we will create a registration and login page to create and login as a user, using a username and password. After this, the user can post a status and see a list of all the other user's statuses. A comment can be also posted in a status. 

Now we will start to design and develop our server-side project using Spring.