Speaker details

Jarek Ratajski

Engenius GmbH

I love programming since my first line of code I did on  the C64  in Basic. Somewhere in 90ties I've switched from C++ to java and spent then 18 Years developing mostly Java software working for various companies and projects.  Now I work for Engenius in Switzerland being Java/Kotlin developer during the days and Scala/Haskell open source hacker at nights.

Spring, Jakarta EE, CDI and other pathologies


If You code in Java You probably deal with the frameworks mentioned in the title. Maybe You even started to believe that they help You to write code faster, safer and easily testable. Well, that is just marketing. You encounter and solve problems cause by those platforms everyday and You simply ignore the costs ... because You do not know the alternatives. In this session I show why the king is naked (all the kings), why no serious project should use all those Bean based frameworks on production. I will show problems are caused by container dependency injections and present more then 10 reasons why annotations such as @Transactional fail miserably - and You do not even notice. Platforms that were created to solve problems of distributed programming and web development 20 years ago do not really help us that much in 2019. For, we have really better and safer alternatives now.

Scheduled on Saturday from 17:40 to 18:30 in Room 5

Dependency Injection Solution
Functional Java
Enterprise Java

Lambda core hardcore

Programming languages

Since Java 8 – so called lambda expressions can be used by Java developers. But what does it mean... Lambda? The talk will be about story behind this term, from a little bit more scientific point of view. Church Lambda calculus, Entscheidungsproblem and incompleteness theorem. Almost all of that will be presented in Java – in the language that you understand. And of course you can later impress your friends with some impressive math tricks. There are going to be shown some very crazy code pieces such as perfectly unusable implementation of boolean (based on lambda expressions). Come and see what purely functional really means.

Scheduled on Friday from 13:10 to 14:00 in Room 7

Church Lambda
Lambda Calculus
Functional Programming