The blog post by Rain Leander details a comprehensive guide for building and deploying a cloud-native web application using Java, Spring Boot, JPA, and CockroachDB. The project involves creating a leaderboard application that stores video game scores in a CockroachDB database hosted on its serverless platform. Key steps include setting up a CockroachDB cluster, configuring a Spring Boot application with Maven and necessary dependencies, and developing the web app with HTML pages using Thymeleaf. The application is then deployed on Heroku, leveraging its platform-as-a-service capabilities to streamline the deployment process. The guide also covers database setup, application architecture, and creating a repository on GitHub for version control. Additionally, it provides instructions for testing the application by adding and viewing leaderboard entries through a web interface, demonstrating the integration of CockroachDB for data storage and management.