problem VS Grails

Zalando RFC 7807 Java Implementation

That's a silly question. Yet, I'd probably answear https://github.com/zalando/problem-spring-web (which is a Spring extension for https://github.com/zalando/problem).

And frameworks like Grails build conventions and helpers on top of Spring.

I don't have any direct experience and am only suggesting it because you mentioned RoR...But Grails (https://grails.org/) is basically the JVM version of RoR (Groovy on Rails -> Grails).

Grails - Spring under the hood. Much less boilerplate. Opinionated, which helps keep things consistent. Uses Spring-Security plugin for authentication.

Also, Grails, which a Rails like framework build on Groovy, a JVM scripting language.

Any JVM language to the rescue here? There’s one, but it’s not the one you’re thinking about. In a sign that this index may not accurately reflect our project reality, Groovy saw a meteoric rise of 0.86% to 1.04% last year! That was good for place 17. Yep, Groovy! Are people writing Gradle plugins in Groovy? Or is Grails having a resurgence? I’m as baffled as you are.