Backend Architecture Example
A Spring Boot demo application built around Java 26, showcasing modern Java features, API development, interview exercises, SQL/JPA demos, and practical backend engineering patterns.
Java 26 Demo is a hands-on sandbox designed to explore current Java capabilities while demonstrating software engineering fundamentals. It includes examples from multiple Java releases, interview-style exercises, polymorphism scenarios, SQL and JPA demonstrations, and API-first development. Swagger documents the REST endpoints, while the GraphiQL explorer provides an interactive way to inspect and run GraphQL queries. The project is deployed on AWS Elastic Beanstalk and uses Docker to containerize the application.
Explore language features from Java 8 through 9, 10, 11, 21, and 26.
REST endpoints showcasing repositories, queries, relationships, and data access patterns.
Swagger UI, OpenAPI, and GraphiQL make the REST and GraphQL APIs browsable and easy to test.
Browse and query the in-memory H2 database directly during local development.
A separate module demonstrates the Java Platform Module System.
Run locally, package as a JAR, containerize with Docker, or deploy to cloud hosting.
GraphiQL is an interactive workspace for the /graphql API. Unlike a REST endpoint with a fixed response, GraphQL lets you request only the fields you need and follow relationships, such as an employee's team, in the same request.
Use the GraphiQL link below when the Java API is online.
Open the Docs panel to browse queries, arguments, types, and available fields.
Paste an example into the editor and press Execute or Ctrl+Enter.
The response pane shows JSON containing exactly the fields you selected.
Returns employee details and follows each employee's relationship to a team.
query EmployeesWithTeams {
employees {
id
name
department
salary
bonus
team {
id
}
}
}Passes an ID to fetch one record and selects a smaller, focused response.
query EmployeeById {
employee(id: "1") {
id
name
department
phoneNumber
team {
id
}
}
}If a query returns no records, run this mutation to restore the organization demo data, then retry the query.
mutation ResetOrganizationDemo {
resetOrganizationDemo
}Try this: remove salary from the first query and run it again. The field disappears from the response, demonstrating how GraphQL gives the client control over the returned shape.
I built Java 26 Demo to use Java functions too modern to make it into most entierprise tech stacks. Here I've reinforced backend fundamentals and packaged that learning into a cohesive, browsable application. It works as a practical reference, an interview preparation aid, and a portfolio-quality project that demonstrates architecture, language features, data access, documentation, and AWS deployment.