Vavr - Functional Java the Easy Way


Wir freuen uns über Eure Anmeldung (optional und unverbindlich) auf unserer Meetup-Seite.


Der Vortrag findet am 15.11.2017 um 19:00 Uhr im Mafinex Teil C, Julius-Hatry-Straße 1, 68163 Mannheim-Lindenhof im Besprechungsraum C4 statt (Anfahrtsbeschreibung).


Bring your Laptop. We will write some Vavr-Code.


This talk will introduce you to Vavr, a library that borrows heavily from Scala and applies Scala’s ideas to plain old Java. We will cover some of the productivity enhancements and syntactic sugar that Vavr offers, such as pattern matching aka. structural composition, value types and functional data types.

Vavr can be a building block for functional business code, that is easy to maintain and understand. It consists of a broad set of ideas and enhancements to Java and makes developing in a more-or-less functional style so much easier. Developers that have tried Scala but have to develop business assets using Java do not have to despair anymore.

This quick overview shows how to improve business code using Vavr using actual code from our projects (although anonymized for obvious reasons) and give a taste of the features and benefits a small library like Vavr offers.


David Schmitz is pricinpal architect at Senacor Technologies with a history of + 13 years of working in various projects using a bunch of different stacks and environments. Current focus is on migrating architectures and organizations, such that our customers can cope with the challenges of the digital age.

Agile Java Day (aka Venkat's 50 JUG tour)


In order to plan for this event we would politely ask for registration via our Meetup page. Around lunch time we will get Pizza and drinks.


Saturday, Jan 27th 2018 from 09h until ca. 16:30h (4 talks at 90 mins each).


The talk will be held in English.


Venkat Subramaniam is a widely known author and speaker at many international conferences. As part of his world-wide 50 JUG tour he will come to Mannheim (the only stop in Germany!) for a day of teaching on Java topics. We are looking forward to have him presenting the following topics:

Exploring Java 9

If Java 8 was all about how we code, Java 9 is all about how we will build. Modularization will have the biggest impact of any change that happened in Java since its inception. In this presentation we will learn about the need for modularization, how it impacts development, the rules to follow when creating modules, and the effect it has on legacy code. We will explore creating module, using modules, readability, exports, automatic modules, and unnamed modules.

From Functional to Reactive Programming:

We’re in the midst of renewed interest in functional programming. At the same time we see quite a bit of excitement around reactive programming. Where did reactive programming come from? How is it related to functional programming, if at all? In this presentation we will discuss the merits of reactive programming and how functional programming concepts seamlessly transition into the programming model espoused by reactive programming.

The Power and Perils of Parallel Streams

“If streams can be parallel, why not make them parallel all the time?” is a common question from developers getting introduced to Java 8 streams. In this talk we’ll take on three separate topics. 1. When to consider parallelization and when not to. 2. How to parallelize, how to decide on number of threads, and how to control the threads pool. 3. Learn about some common mistakes people make when using parallel streams. The goal of this talk is for us to learn when and how to make good use of parallel streams.

Twelve Ways to Make Code Suck Less

We all have seen our share of bad code and some really good code as well. What are some of the common anti patterns that seem to be recurring over and over in code that sucks? By learning about these code smells and avoiding them, we can greatly help make our code better. Come to this talk to learn about some common code smell and how to improve the quality of code.


Dr. Venkat Subramaniam is an award-winning author, founder of Agile Developer, Inc., creator of, and an instructional professor at the University of Houston. He has trained and mentored thousands of software developers in the US, Canada, Europe, and Asia, and is a regularly-invited speaker at several international conferences. Venkat helps his clients effectively apply and succeed with sustainable agile practices on their software projects.

Venkat is a (co)author of multiple technical books, including the 2007 Jolt Productivity award winning book Practices of an Agile Developer. You can find a list of his books at You can reach him by email at or on twitter at @venkat_s.