Build Even Faster Quarkus Applications With fast-jar Quarkus is already fast, but what if you could make inner loop development with the supersonic, subatomic Java framework even faster? Introducing the fast-jar format! by Join the DZone community and get the full member experience.Join For Free Quarkus is already fast, but what if you could make inner loop development with the supersonic, subatomic Java framework even faster? Quarkus 1.5 introduced fast-jar, a new packaging format that supports faster startup times. Starting in Quarkus 1.12, this great feature became the default packaging format for Quarkus applications. This article introduces you to the fast-jar format and how it works.