In this talk Mike discusses two different projects: one is the largest enterprise Kotlin project to date, and the other is the exact opposite, a small command line tool that generates standalone ahead-of-time compiled native binaries for Kotlin/JVM programs. Find out how and why a consortium of banks chose to use Kotlin for a next-gen blockchain platform, and how you can use Kotlin to write small command line tools that compete with Go. Mike Hearn is lead platform engineer at R3, a startup and consortium of the world's leading financial institutions. He leads the build of Corda, a blockchain-inspired distributed ledger platform that simplifies and streamlines business, implemented entirely in Kotlin. Mike spent nearly eight years at Google where he was a senior software engineer, and five years as a Bitcoin developer. He first used Bitcoin just four months after it was released, and went on to develop one of the leading open source implementations of the protocol (bitcoinj). BitcoinJ ended up being used in hundreds of products that had between them millions of users, as well as being a frequently used platform for academic research. Mike was an early adopter of Kotlin and started using it about 18 months before version 1.0 was released.