This is a collection of articles I wrote over the years, presently with a strong focus on building reactive systems with Akka.

10000 nodes and beyond with Akka Cluster and Rapid

Published on 30 April 2020

Update: there’s a podcast episode about this The year is 2021. As the world is still deeply affected by the COVID-19 pandemic, the United Nations have decided that in order to prevent […]

Tour of Akka Typed: Cluster Sharding

Published on 9 November 2019

Update 21/11/2019: Fixed comment about shardId extraction in relation to ShardingEnvelope Welcome to the fifth part of the Akka Typed series! In this part, we’ll leave the safe harbor of a single […]

Tour of Akka Typed: supervision and signals

Published on 5 September 2019

Update 18.10.2019: fixed wrong syntax for handling multiple exceptions, clarifying a few points Welcome to the third part of the Akka Typed series. In the first part we had a look at […]

Raspberry PI Akka Cluster LED strips

Published on 2 May 2019

Ever since Eric Loots from Lightbend first showed me the Raspberry-PI based Akka Cluster with special LED stripes, I’ve wanted (at least) one of them. This is a 5 node cluster with […]

Akka anti-patterns: too many actors

Published on 6 August 2018

Update 07.08.2018: clarified optimal vs. suboptimal use cases of having many actors at runtime (it could have been misunderstood that Akka isn’t meant to build systems with many actors – it entirely […]

Tour of Akka Cluster

Published on 3 August 2018

Here’s an overview of the Tour of Akka Cluster article series: Tour of Akka Cluster – Akka Distributed Data Tour of Akka Cluster – Eventual consistency, persistent actors, message delivery semantics Tour […]

Akka anti-patterns: Java serialization

Published on 20 July 2018

Akka makes use of serialization when messages leave the JVM boundaries. This can happen in mainly two scenarios: sending messages over the network when using Akka Cluster (do not use Akka Remote […]

Akka anti-patterns: stateless actors

Published on 30 May 2018

Actors are object-orientation done right (as opposed to say, objects in Java): their state is not visible from the outside and they communicate via messages. There’s no way to break encapsulation because […]