• First experiences with Akka Typed and Scala 3 / Akka Persistence Typed

    Tonight we have two speakers, Eric Loots and Renato Cavalcanti.


    18:00 - Doors open / Pizza & Drinks

    19:00 - First experiences with Akka Typed and Scala 3

    The release of Akka 2.6 was received with a lot of excitement in the community. A major milestone in this release was the marking of the Akka Typed APIs as stable. In the process of migrating an existing application from Akka Classic to Akka Typed, not only did I learn a lot but I also started to appreciate the great design of the APIs.

    In an unrelated thread, there was the announcement by the Dotty team that, as of now, Dotty is feature-complete for Scala 3. With a scheduled availability of the first release candidate for Scala 3 around the end of this year, the time has come to start looking at what Scala 3 can bring to the Scala ecosystem.

    With the above in mind, we will look at the following topics during this talk:

    - Experiences during the migration of an application from classic to typed
    - What can Scala 3 bring to Akka Typed?

    20:00 - Akka Persistence Typed

    In this talk, we will introduce you to the new Typed APIs for Akka Persistence and its new integration with Akka Cluster Sharding.
    Although type-safety is the coolest thing we are getting from Akka Typed, the new persistence API is more than just types. There are also a few API improvements that will help you write better and safer persistent actors. We will cover the existing pitfalls in the untyped API and how they have been solved in the typed API.

    21:00 - End of meetup


    Eric Loots is a 35 year veteran in the IT industry. Having served in the business for such a long time has given Eric a holistic view on the evolution of technology: he started his career with programming different microprocessors using assembly language, witnessed the birth of Java while being at Sun Microsystems and discovered Scala and Akka about 7 years ago.
    Eric's the creator of the Akka Cluster on Raspberry-Pi project which has become quite popular and has helped many to understand Akka Clustering in an enjoyable and playful way.
    Eric is CTO at Lunatech Belgium.

    Renato is a software developer at Lightbend where he works in the Play/Lagom Framework Team. Scala aficionado since 2009, he has been hacking in Scala and related technologies for fun and profit. He has a special interest for Event Sourcing/CQRS, DDD and Microservices Architectures. He's the founder of BeScala (Belgian Scala User Group) and maintainer of Play and Lagom Frameworks.

  • The Evolution From Monolith to Microservices to Serverless and Beyond

    This is an event organised by the BruJUG, but I'm double posting it here to increase awareness. Please, go there to subscribe.


    WATCH OUT: don't put your name on the waiting list here. It's normal that there is only one seat. Go to the BruJUG URL to subscribe.


    If you are a developer or an architect, the odds are that you grew up building systems that are now commonly known as monoliths. In the last few years, we've seen a significant evolutionary shift to systems composed of microservices.

    Today we are witnessing the birth of serverless. The rate of evolutionary change is accelerating. But what is changing, and what remains the same?

    In this talk, we will look at the evolution from the monolith to serverless seeking to extract the variables and the constants. We will also look at the progression from serverless to an inevitable future of frictionless computing.

    About the Speaker:

    Hugh McKee is a developer advocate at Lightbend. He has had a long career building applications that evolved slowly, that inefficiently utilized their infrastructure, and were brittle and prone to failure.

    Hugh has learned from his past mistakes, battle scars, and a few wins. And the learning never stops. Now his focus is on helping other developers and architects build resilient, scalable, reactive, distributed systems.

    Hugh frequently speaks at conferences. He is the author of Designing Reactive Systems: The Role Of Actors In Distributed Architecture.

  • Tame Crypto Events with Streaming

    Startup Village

    How do you tame the chaotic world of cryptocurrencies, with all that data that doesn’t seem to make any sense?
    The only possible answer is Reactive Systems and controlled streaming. Our goal is to find reliable patterns between events relative to a cryptocurrency (like a conference or a fork) and its relative price fluctuations. We need an always-on system that gathers this data from different sources, and we can’t afford missing data because of downtimes.
    This talk covers all the steps of a reactive data project. We start with domain modelling with DDD and Event-storming, then touch on the implementation side with a back-pressured toolkit like Akka Streams, run our services on Google Cloud’s Kubernetes and finally look at the data we gathered trying to find patterns. Lambos have never been so close.

    Fabio is a software engineer, conference speaker, and community leader based in Amsterdam. While building his own start-up, he fell in love with Akka, Scala, and Reactive systems, so much so that he founded the 2000-member strong Reactive Amsterdam meetup group. When not in front of a screen, he enjoys long distance bike rides and fingerpicking his guitar.

  • How to test proper{t,l}y


    Writing unit tests is pretty much-established practice and in addition to that, property testing has caught up on popularity. Most functional languages have one, sometimes even many implementations. But “property testing” has a lot of aspects: randomized or exhaustive, minimization and generalization of counter examples, custom generators and filters, to name a few. Very often, property tests don’t exploit all the features of the framework. In this talk, I’ll give an overview of the state of the art of property testing in FP languages and show some common use cases, techniques and pitfalls.

    Lars is a consultant with INNOQ in Munich, Germany. He is known as one of the founders of the Typelevel initiative which is dedicated to providing principled, type-driven Scala libraries in a friendly, welcoming environment. A frequent conference speaker, he is active in the open-source community, particularly in Scala. He also enjoys programming in and talking about Haskell, Prolog, and Rust.

  • Introduction to Tensorflow in Scala


    This talk introduces Tensorflow as a Machine Learning framework, using Scala notebooks. Then moving towards Data Science Engineering, we show how serving Tensorflow models can be done with simple and flexible akka-http services. Let’s discuss what the first steps towards akka-tensorflow would look like!


    * 18:00 - open doors and networking (food and drinks)
    * 19:00 - start of presentation

    Bio: Xavier Tordoir, a cool bro, has a scientific background in physical sciences, genomics and financial markets data analytics on distributed system. After academia, he became BigData and Data science consultant. He is author of trainings in Spark, Kafka, Machine learning and Tensorflow, Xavier now works at Lunatech on the development of the BigData and AI branch.

  • Meet Akka gRPC

    Cronos Leuven

    This is a meetup at the Reactive Programming Belgium Meetup that I'm cross-publishing here.

    Please, subscribe there instead:

    Our next event will be a co-op with the Belgian Scala User Group. Our guest speaker is Renato Cavalcanti who works for Lightbend (formerly Typesafe), the company behind the Scala programming language, Akka and Lagom. Akka & Reactive Programming are a perfect match, using the concepts of the Actor model & Akka Streams.

    In this talk, Renato will give an introduction to Akka gRPC and how it can be integrated with Akka Http, Play and Lagom.
    gRPC is a schema-first RPC framework, where your protocol is declared in a protobuf definition, and requests and responses will be streamed over an HTTP/2 connection.

    Based on a gRPC service definition, Akka gRPC can generate model classes, service API (backed by Future and Akka Streams API), server infrastructure and a gRPC client.

    Welcome with food & drinks
    Start presentation
    Drinks & networking

  • Scalaz-ZIO Queue


    Wiem will introduce the Queue type that is powered by the Scalaz 8 effect system. Now a core part of ZIO, Queue is built on powerful concurrent data structures, such as Ref and Promise. Wiem will discuss these interesting data structures and demonstrate how to use them to solve real world problems. By the end of the presentation, you'll learn about the power of functional programming to solve the hard problems of software development in a principled way, without compromises.

    About Wiem Zine Elabidine

    Wiem Zine Elabidine is a Scala engineer and a functional programming enthusiastic. Outside of her day job, she loves contributing to Scalaz ZIO projects.
    Wiem is a personal mentee of John De Goes and she was honored to collaborate with him on the first version of Queue.

  • Kotlin vs Scala

    Startup Village

    We have almost 20 years of Scala experience between us and have experience with many other languages. Recently we have jumped onto Kotlin because it looks very promising as Java competitor.
    Of course, there is no one size fits all solution. We will show how the two languages compare and explain why and when you should pick one over the other. Or maybe should consider some else altogether.

    Joost Heijkoop
    Passionate software craftsman working for Xebia and organiser at Amsterdam.scala & Kotlin.amsterdam, always looking to learn, share, help, teach and meet new people

    Urs Peter
    Urs is a seasoned software engineer and trainer with over 15 years of experience in building resilient, scalable, mission-critical systems on the JVM mostly using Scala and Java, with Kotlin as a recent addition. Besides his job as a consultant, he is also a passionate trainer who has taught and mentored over more than two hundred developers in getting mature with the Scala ecosystem and reactive programming. As a people person by nature, he loves to share knowledge and inspire pears on meetups and conferences.

  • Meet and Greet Lagom Team


    The Lagom Team is holding a team meeting in Leuven next week and we thought that it will be a great opportunity to organise a BeScala summer drink at the Oude Markt.

    There will be no presentations, just informal drinks. Hopefully on a nice summer terrace.

    We don't have yet a fixed place to meet. Probably at the Metropole, but it all depends on the place availability at runtime. Just look around, we will be somewhere at the Oude Markt, scheduled on some beer tap thread and letting the stream flow.

    You are all welcome!