Stuart Williams explains vert.x: basic idea and architecture, how it uses Java's NIO and async APIs, how it allows using various JVM languages (Groovy, JRuby, Scala, etc), the EventBus and much more.
Bob Lee explains the popularity of Java, future language features like Lambdas, DI with Guice vs. the Dagger framework, the role of Java vs. Ruby at Square, hiring at Square, security and much more.
Debasish Ghosh talks about the advantages of functional programming and how its abstractions help to reason about code, Monads, DSLs, NoSQL and MongoDB, and much more.
Ken Little talks about scaling Tumblr to keep up with their blogging users: scaling the data model, sharding, their PHP frontend and the Scala backend, and much more.
Phil Trelford discusses how to design large scale applications with functional concepts, the state of the F# community and much more.
Rúnar Bjarnason talks about the ideas behind and features in the popular scalaz library, programming concepts like (bi-directional) lenses, Scala Macros, and much more.
Miles Sabin explains dependent typing in Scala, the Shapeless project that demonstrates these concepts, static typing improvements in Scala and Scala Macros.
Lance Walton discusses Scala in the enterprise, educating developers in functional programming and whether Scala's binary compatibility issues between releases are a problem, and much more.
Dick Wall explores the state and future of Java, his reasons for switching to programming in Scala, the SubCut Dependency Injection library for Scala, Scala Compiler Plugins and much more.
Sadek Drobi discusses functional programming sand Scala's multi paradigm approach at QCon London 2012. He also shares insights into the new Play 2.0 framework.