On the weekend, I had a pleasure to once again attend Scalar. This is annual Scala conference, which is held in Warsaw. The 2015 edition was very similar in the form to the previous one.

It was one-day event with 13 speakers giving 30-minutes talks on specific topic in front of an audience of something like 500 people. And some of those speakers were already known within the Scala community (at least our local, Polish one). I must say that some of them shown great presentation skills at times. Some of the covered topics are: web development, news from Typesafe (like Akka, Slick roadmap), low level performance, distributed functional programming, api design, graph databases. There were some interesting talks among them. Let me put a comment on some of them in the next few paragraphs.

My personal favourite was the talk of the organizer’s representatives: Tomasz Szymański and Adam Warski. They presented Supler, the library that they work on in order to simplify building web forms. Supler can be easily used within various web frameworks (like Play, Spray). The concept of this library is that you can define form logic in a single place (on the backed) and use this single definition to generate html view, client side javascript code for both validation and submission and use it also for server side validation. After their live demo, my feeling was: that’s how it should be done. The authors really impressed me with their idea. I am not sure how production ready Supler is, but IMO it looks very promising indeed.

I liked also Konrad Malawski (from Typesafe) presentation. He presented the overview of new features in Akka that are going to be implemented in the next version of the library. He also talked about independent API specification for Reactive Streams on the JVM (and how Akka Streams will support it). As Akka fan, I am glad that the library is developed further.

Jamie Allen (author of Effective Akka and Senior Director of Global Services for Typesafe) was the one gave the most low-level presentation of the day. He spoke about data immutability and its importance for effective usage of multi-core processors. Most of the content should already be known for non-beginner Scala developers, but still, I managed to learn some interesting stuff. Jamie explained what is the most effective way of using “volatile” keyword and how to arrange variable access/assignment order to have both the guarantees you need (most fresh data available to all threads) and performance.

Author of rapture.io, Jon Pretty, presented some cool insights on how to design fault-tolerant API – mainly focusing on strategies of exception handling. Most of his ideas were presented on his handy and elegant in use JSON parsing library.

Scalar’s speakers with the full audience in the background

Except of the presentations, which are the main course of such conference, there were other opportunities to learn about fresh stuff from Scala community. Personally, I’ve learned about cool online “newspaper” with all the Scala news – which is released every week – Scala Times. I will be definitely looking at it every once in a while.

I am happy that I could attend the conference. It’s always cool to meet others who are interested in Scala, just like you are. And all of the ideas you are seeing here, make you wonder if there are some stuff you might be doing differently in your daily work :)