Quark is a new Scala DSL for data processing and analytics that runs on top of the Quasar Analytics compiler. Quark is adept at processing semi-structured data and compiles query plans to operations that run entirely inside a target data source. In this presentation, John A. De Goes provides an overview of the open source library, showing several use cases in data processing and analytics. John also demonstrates a powerful technique that every developer can use to create their own purely-functional, type-safe DSLs in the Scala programming language.