Spark-a-thon — Developing Spark Extensions (using Scala)

Time to learn how to develop extensions to Apache Spark using the best programming language Scala. Place is not confirmed yet, but the meetup will happen anyway. Let's be brave! Bring your laptops, JVMs, and IntelliJ IDEA. Clone the Spark repo or stay with Spark 1.6.2 if you like. The fun is on master, though. It is about extending the platform itself (not necessarily about writing Scala apps using Spark). Use comments below to build the agenda first. What would you like to have covered?