Dan Vega and DaShaun Carter hosted Felipe Gutierrez on their Spring Ecosystem updates. They discussed the newly released book "Pro Spring Boot 4: An Authoritative Guide with Best Practices" co-authored by DaShaun and Felipe. The book covers topics like Spring Boot 4, Spring Security, GraalVM, AOT, Testcontainers, and AI integration with Spring AI. Viewers were invited to join the live stream or catch the replay on podcast platforms.