Thanks so much. We spent a long time thinking about how to have the benefits of types in a Clojure-y data-oriented way. The advantage of having Schemas as data is that we can use Clojure code to process them and generate things like Objective-C classes (https://github.com/Prismatic/schema/blob/d82bf0b049fc1205a81...) and Avro specifications. It will be our glue to declarations in other languages.