Frank's work utilizes the Jolt spec(Apache 2 license), which is a great way to handle JsonToJson transforms in my opinion.
Jolt is not a good fit for Process or Rules, (Use Groovy or Java, etc), but transforming Json in a great declarative way with Jolt beats the pants off of anything else out there. Although its not stream based, and can consume memory when your Json payload size is huge, like 300mb json files, etc, but fine for most Json payloads in the wild. "Two things to be aware of : 1. Jolt is not "stream" based, so if you have a very large Json document to transform you need to have enough memory to hold it. 2. The transform process will create and discard a lot of objects, so the garbage collector will have work to do. " A few more details about how it can be used are mentioned on its official page here: http://bazaarvoice.github.io/jolt/ A demo of Jolt to see how you can transform Json to Json (click the Transform button): http://jolt-demo.appspot.com/#ritwickgupta Here's the rough performance of Jolt in 2013 where an 80k json file is shifted in about 5 secs. (authors notes on this slide are interesting), : https://docs.google.com/presentation/d/1sAiuiFC4Lzz4-064sg1p8EQt2ev0o442MfEbvrpD1ls/edit#slide=id.g9ac79e71_01 Thad +ThadGuidry <https://www.google.com/+ThadGuidry>