Lgd. Viktor Klang

Systems all the way down

Viktor Klang bio photo


I am Viktor Klang, an explorer in the realm of software, mostly specializing in Developer Experience, API Design, Software Architecture, and Concurrent & Distributed programming models.

In my professional career I have always gravitated towards enabling others to be more productive, and ss a result of this I have contributed to the standard libraries of several major programming languages, been involved in many Open Source projects, and enabled some of the largest companies in the world to bring novel solutions to market.

⚡️Views are my own. ⚡️

Professional highlights

In 2023, I proposed «Stream Gatherers» as Java JEP-461. «Stream Gatherers» augments Java Streams (java.util.stream) with an API which allows the definition, composition, and execution of custom intermediate operations.

Between 2019 and 2021, together with my colleagues Jonas Bonér and James Roper, I created Kalix—a novel platform which allows developers to create stateful serverless applications without ever having do deal with a database, using practically any programming language.

I was one of the earliest, and most prolific, contributors to the Akka Project, which was started by Jonas Bonér. I was Akka’s Tech Lead between 2011 and 2012—preceded by Jonas Bonér and superseded by Roland Kuhn.

In 2013 I helped found the Reactive Streams Initiative which I have since then stewarded, together with a group of world-class contributors.
There is now a JVM version and a .NET version, and it is included in Java 9.

I co-authored Scala Improvement Proposal 14scala.concurrent—in 2012, and maintained it for 10 years.

Also, I am a co-author of Scala Improvement Proposal 20 (improved lazy val initialization).

I’ve been ranked, by Computer Sweden, amongst the Best Software Developers in Sweden, as the 11th (2016); 18th (2015); and 15th (2012).

In 2018 I was elected Java Champion.

Career summary

Since September 2022 I am a Software Architect in the Java Platform Group at Oracle where I primarily work on OpenJDK.

Between June 2021 to September 2022 I was Director of Engineering at Sinch where I was responsible for making sure that developers using Sinch products have effortless success, and that developers at Sinch can deliver value without friction.

Between 2010 to 2021 I worked for Lightbend Inc. As the first employee of what was initially called «Scalable Solutions» my responsibilities changed over time: from IC on the Akka team; to leading it; to becoming the first Dir. Eng. in the company; then Chief Architect; between 2015-2020, I served as Head of Cloud Engineering and Deputy CTO, to then in 2020 I became Vice President of Engineering, Cloud where I was responsible for creating Akka Serverless, which I co-created during my time at the Office of the CTO, and subsequently, together with my organization, took to production.

Between 2003 and 2010 I worked for Yves Rocher Suéde AB building their «Next Generation» Enterprise Management System—everything from CRM, ERP, WMS, Billing, Marketing, Statistics, Payment processing, the works… I started as a Junior Software Developer and left as Systems Architect.

Public speaking engagements















  • Devoxx BE
  • W-JAX
  • Lunds Tekniska Högskola - Campus Helsingborg
  • Gothenburg Scala Enthusiasts
  • ÖreDev
  • Scala Days