Past Meetup

λ: Streaming with FS2 // Sync considered unethical

This Meetup is past

37 people went

Location image of event venue


Welcome in 2019!

We hope that you had great holidays and some of your New Year's resolutions include λs, because the first meetup of the year is all about functional programming! We invited two guest speakers, who will present their approach to some of the hottest Scala FP topics.

1. "Stream or not to Stream? FS2 is the answer" (Łukasz Byczyński)
Streams are often underestimated and skipped as possible solutions. In many cases, we created much more complex solutions than their streams counterpart. Why?

It's hard to answer, but in this presentation, I would like to tell you a story about how we started to use FS2, without sacrificing purity and code readability. (

2. "Sync considered unethical" (Tomek Kogut)
Scala over the past few years has become more and more inclined towards the pure FP. Most of the techniques and concepts are coming from the Haskell programming language. Some of those are already considered obsolete, some are being adjusted to what Scala is and some new might be just heading our way to show up during 2019 Scala conferences. Let's try to look where all of this have led us. Compare it to some of the works done in real world Haskell. We'll see if it brought us any closer to the liberation from the von Neumann paradigm. Last but not least we'll try to answer the question: are we any better than our colleagues doing plain old imperative programming?

About our speakers:

Łukasz Byczyński (
I started as coder since from I get my first 8-bit computer - C64. It was a long journey for me, from a machine assembly code to the pure functional constructs. Right now, I'm passionate about designing pure architectures with reasonable costs.
I'm a part of the team responsible for build the platform for implementing machine learning algorithms in Adform.

Tomek Kogut (
Technical Lead in Adform’s research department. He gained his programming experience from creating low-level kernel modules in C / C ++ through telecommunications systems written in enterprise Java to ETL big data pipelines. His favorite programming language since 2011 is Scala. He likes and appreciates the functional approach to programming, but tries to keep an eye on the efficiency of the solutions he creates. In everyday work in Adform he builds with his team the best platform for implementing machine learning algorithms.


As always there will be some beer, contests and JetBrains' licenses to give away! See you in Metaforma!