Ask HN: Modern Web Dev on the JVM – How does the stack and tooling look like?

I work as a data analyst and therefore have mostly been dealing with Python and R (both in exploration and to deploy services). We recently switched to h2o as our analytics engine, which lets you save your models as Java objects. Our goal is to create a template for a prediction microservice on the JVM to make using the models in production straightforward (I.e. Save the prediction model, implement the endpoint, deploy).

The question is now: What tooling is consider best practice? What JVM language would be most appropriate for small services (that can still easily interface with Java)? Any good micro web frameworks?