In this chapter, we've learned about Spring Security and how it works internally. We also briefly reviewed how Single Sign-On and OAuth 2.0 work. We've also implemented the login page's frontend and backend, as well as using Spring Security's PasswordEncoder to encrypt passwords. We've also implemented a feature for sending email using JavaMail and FreeMarker. We've improved our end-to-end testing by using Page Object and generating test user data, as well as running the test against http://localhost:8080 during the full build with the mvn clean install command.

In the next chapter, we will implement the home page, and we will focus on the use of Vuex, as well as the technique of mocking RESTful APIs to get more freedom for the development of the frontend.