Orbis Connect hosted our second JVM Wars last night online. Our panel discussed the JVM languages, from their levels of productivity through to their best-suited functions. Java, Scala, Kotlin and Clojure... but which one is the best?

"The best bit about having other languages (apart from Java) on the JVM is that it's forcing evolution" 

We also discussed other languages on the JVM, other than Java, Scala, Kotlin and Clojure, and which one the panel would choose. There were suggestions of Haskell, Python, Zig and the new language, Unison. Check out the full Q&A below. Links to the panel slides can be found further down this post. 

The final poll results were close by the end, with SCALA coming out on top!

Event Host:

Aaron 'Shakey' Shakeshaft - Senior JVM Consultant, Orbis

The Panel: 

Ben Gamble –  Representing Java 

Ben Gamble is the Head of DevRel at Ably, a protocol agnostic, globally distributed data streaming network. He’s spent the last 10 years in a range of startups and high growth companies, Bridging the gap between research and product development. Having worked with the cutting edge of Augmented reality, scaling 3D gaming, and wearable tech, he's no stranger to taking on technical challenges, and the commercial realities that entails. Ben now works to make real time data a reality for anyone who needs it, and make as much of it open as possible through Ably’s open data Hub.


Adam Warski – Representing Scala 

Adam is one of the co-founders of SoftwareMill, where he codes mainly using Scala and other interesting technologies. He is involved in open-source projects, such as sttp, tapir, Quicklens, ElasticMQ and others. He has been a speaker at major conferences, such as JavaOne, LambdaConf, Devoxx and ScalaDays.

Apart from writing closed- and open-source software, in his free time he tries to read the Internet on various (functional) programming-related subjects. Any ideas or insights usually end up with a blog. (

David Denton – Reprenting Kotlin 

Principal TDD Polyglot, Trainer, Lean Coach & Open Source fanatic.
Highly experienced Tech Lead polyglot specialising in TDD, software craft, debt resolving, mentoring and straight talking. Particularly specialised with ContinuousDeployment solutions: Java, Kotlin, Scala, Node & a quick study in others. Infrastructure-as-code automation. Build-craft. Refactoring wizard. Legacy-code cleaner.

Creator of both http4k (Kotlin - and fintrospect (Scala - web frameworks

John Stevenson – Representing Clojure 

Experienced software engineer across a range of domains. John has enjoyed working with leading-edge consultancy companies and financial institutions, building solutions with Java/JVM technology and agile practices. Functional Programming with Clojure / ClojureScript has been John’s focus for the last 5 years.

He is involved in growing the London Java Community, London Scala User Group and currently the London Clojurians community over the last decade.

Currently Chief Fun officer at






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