OpenAPI and Spring-Boot 4 - What's New?
Badr Nass Lahsen - CyberArk
Spring Boot remains the most widely used Java framework for modern application development, powering millions of applications globally. With Spring Boot 4, the framework enters a new era of performance, cloud-native support, and developer productivity.
This talk will showcase the key innovations in Spring Boot 4 — including built-in API versioning, improved performance and integrations, — that make it a powerful choice for building scalable APIs.
A major focus will be on OpenAPI and its integration via springdoc-openapi, a community-driven project that now exceeds 300 million downloads per month. We’ll dive into the core features of springdoc-openapi, including support for the new Scalar project, an alternative to swagger-ui, Spring MVC, WebFlux, GraalVM, Kotlin.
You’ll also learn how to leverage advanced features like actuator integration, Javadoc reuse for API descriptions, HATEOAS, Data REST, and OAuth2 security.
The session will also cover historical version support in Spring Boot, illustrate how OpenAPI is transforming the developer experience, and explore modern tooling for CI/CD pipelines with Gradle/Maven for API documentation generation.
We’ll also touch on microservices use cases with Spring Cloud Gateway and serverless integration with Spring Cloud Function. Whether you’re modernizing legacy APIs or building greenfield microservices, this session offers practical insights and resources to accelerate your API-first development journey.