To play devil's advocate, a software craftsperson would ideally use the right tools for the job. You could fire up Groovy and Spring for a REST API that essentially takes JSON from a source/sources, transforms, and returns... but there are easier languages and frameworks and much more performant ones.

The developers I've met with this argument have usually been doing one stack for many years and don't want to do anything new or uncomfortable. It's like watching someone try to cut brush with a butter knife.