A project from JetBrains Academy:
There is a lot of collaboration in programming: many projects require sharing your code with other developers. Using open web resources such as Pastebin is not always an option. In this project, you will create your own secure version of a code-sharing platform.
You will get acquainted with server development on Spring Boot and touch on some basic topics in Web-programming such as HTML, CSS, and JS.
Project page: https://hyperskill.org/projects/130
This project used to work with Apache FreeMarker, but I migrate it to Thymeleaf.
In addition, it has got a nice, dark, responsive design with Bootstrap.
You can see the code snippet container in action:
Responsive code snippet container (Bootstrap, highlight.js)