Voxxed Days Belgrade – an overview

Last month (1st and 2nd October), the team from Serbia had a chance to attend the biggest Java IT event in Serbia, Voxxed Days Belgrade. This is an IT tech and startup conference and part of the biggest Devoxx events, this year for the first time organized in the Balkans.

Devoxx is an annual European Java conference, created in 2001 in Antwerp by the Belgian Java User Group (BeJUG), formerly known as JavaPolis. JavaPolis quickly became the biggest vendor-independent Java conference in the world. In 2008, JavaPolis changed its name to Devoxx. Nowadays, Devoxx is organized in 5 cities – Antwerp, London, Paris, Krakow and Casablanca. The newly introduced Voxxed Days is an initiative from the Devoxx community. It represents a series of international tech events organized by local community groups and supported by the Voxxed team. Besides Belgrade, Voxxed Days are organized in 9 other European cities (Berlin, Vienna, Zurich, Istanbul, Bristol, Bucharest, Ticino, Algiers, Vilnius).

Organization and topics

The event in Belgrade was organized by HeapSpace, a tech community with a mission to raise awareness about information technology in Serbia. According to organizers, the event is tailored for (Java) Developers, Startup lovers and Geeks 🙂
The conference offered tech talks held by top-notch speakers from leading innovating tech companies. Overall, there were 3 parallel speaker tracks and one workshop track for interested participants. With all those speakers and more than 30 inspiring talks, Voxxed Days attracted more than 500 attendees from various Serbian and regional companies.

Some of the headline speakers included:

  • Ludovic Champenios and Mandy Waite from Google,
  • Juergen Hoeller from Pivotal, co-creator of the Spring framework,
  • David Delabassee and Bruno Borges from Oracle,
  • Simone Bordet, hard-core technology expert, founder and contributor of some well known open source projects such as Jetty, CometD, MX4J, Foxtrot, LiveTribe,
  • Sven Petters, software Evangelist from Atlassian,
  • Iulian Dragos from Typsafe’s Spark team, highly involved in development of Scala programming language,
  • Marcus Eisele and Dejan Bosanac from RedHat and many others…


Three different workshops were organized for all interested participants. There was a huge interest in workshops and all seats were fully booked much prior to conference.
The first one was “Google Cloud Office hours” held by Ludovic Champenois from Google company. The main aim was to introduce Google Cloud to a wider group of developers and users. Official slogan of that workshop was “Everything you wanted to ask about the Google Cloud platform!”
The second one was “Developing Apps with the Wunderbar” where participants had a chance to learn how to start developing with the Wunderbar IoT Platform. It covered onboarding of a sensor kit to relayr account, first steps with the sensors without coding, a live intro to the Java Script SDK and intros to individual SDKs as per request. The Wunderbar consists of a wide range of sensors: temperature, humidity, accelerometer, gyroscope, noise level, light, colour, proximity. It was held by Philipp Richter, freelance Internet of Things consultant.
The third one (and definitely most ‘wanted’) was “Spring Boot & Spring Data” workshop. It presented how to create stand-alone Spring based applications that “just run” using Spring Boot. Participants also had a chance to learn something more about Spring Data module that makes using new data access technologies a breeze. The workshop gave a “hands-on” experience by developing a Spring Web MVC application based on both Spring Boot and Spring Data modules in less than 3 hours!. It was held by Miloš Stanković and Darko Živanović from Serbian company “Pamet”.

Most interesting sessions

Amongst many sessions I would like to give a brief outlook on a few that are really worth mentioning, because they concern the future of certain disciplines in which we are active. Or – in case of the second outlook – give inspiration about a company culture that enhances results both for employees and customers.

The IoT: State of the Art what’s in front of us on that canvas

It was the keynote session and, somehow it marked the entire conference (well, at least in some way). Dejan Dimić, speaker from Smith Micro Software, started his presentation with a funny story about his nutrition program, (smart) refrigerator which keeps track (and BTW, instantly tweets about) of the quantity of food taken from it and his hopeless excuses to his nutritionist who is already informed about it. It was a very smooth and light way to introduce a large audience to matter of Internet Of Things – IoT .

The influence of Internet of Things is such that all researches are aligned in prediction that it will fundamentally change the world we are living in. Regardless it’s still in its infancy, IoT impact is growing quickly. The new rule for the future is going to be, “anything that can be connected, will be connected“.

The presentation made an overview of the main definitions and components, current state of IoT, basic motivations and, most important, it gave some predictions regarding the IoT future.

Coding Culture

For me, it was the most inspiring presentation. Sven Peters, software geek and so-called Evangelist from Atlassian, held that presentation. It wasn’t a fully techie presentation; despite the title, it wasn’t about coding at all. However, it was more an overview of organization culture, about relationships and shared values between Atlassian’s employees, motivation and the way how they treat their customers. As Sven said in the presentation’s official outlook:

It’s about emphasizing transparency and honesty, respecting autonomy, and encouraging collaboration. It’s about maintaining all these things no matter how large an organization grows and protecting that culture by hiring people who will maintain it.

So, Atlassian tried to introduce a nice scheme for defining Cultural values called:
Atlassian Culture which consists of:

  • transparency
  • autonomy & trust
  • balance your passion
  • be one team
  • have the customer in mind.

Due to the fact that it was a too ‘sterile, common and general’ definition, Atlassian transformed it using stickier names, into a new official but more fancy set of values:
Atlassian Values described as:

  • Open Company, no bullshit
  • Be change you seek
  • Build with heart & balance
  • Play, as a team
  • Don’t @#$%@$ the customer

Really, those values could be applied to many other companies, not just in Atlassian.

Messaging infrastructure for IoT

As I’ve already mentioned, IoT was a big hype and one of the main buzzwords at the conference. But this presentation was especially interesting to me because it introduced ‘Integration’ in the world of IoT.
Presenter was Dejan Bosanac, Senior Software Engineer from RedHat who has a deep expertise in messaging and integration. As he mentioned:

Scale changes everything. Number of connections and destinations went from dozen to thousands, number of messages increased by order of magnitude. What once was quite adequate for enterprise messaging can’t scale to support IoT. We need new protocols, patterns and architectures to support this new world.

His presentation started with an introduction to the concept of IoT. After that, he gave general technical challenges involved with the concept and explained why it is becoming mainstream now. It was easy for him to involve audience in messaging patterns, protocols (such as MQTT and AMQP) and tools (Apache ActiveMQ and Artemis) used in these scenarios.
To summarise, IoT offers a new set of problems for communication between devices and backend services. Messaging is a good fit because it provides a wide variety of protocols that can deal with most of these challenges. But some new and different tools and techniques are needed for solving all those problems.
But anyway, even in case of different tools and techniques, big, general expertize in messaging systems as well as in integration is more than helpful. So, maybe some future challenges for all of us 🙂

Continuous Delivery with Docker Containers and Java EE

From RedHat another interesting speaker came, Markus Eisele, Developer Advocate highly focused on JBoss Middleware. He started his session with talking about Java development lifecycle pointing on common problems and challenges:
Customers are impatient, wanting everything NOW and with increased Quality of Service expectations, and
Business seeks for new opportunities and markets with intense competitions BUT with small timeframes to get products and services out.
In traditional approach (Development-Testing-Operations), fulfilment of all those requirements is very slow and unpredictable Therefore, Continuous Delivery was introduced. But it also requires that all necessary environments (like Dev, Test, Staging) should be easily accessible to developers. That’s the point when containers take a big role.
Containers are enabling developers to package their applications (and underlying dependencies) in new ways that are portable and work consistently everywhere. Docker has become the de facto standard for those portable containers in the cloud. Docker slogan says: “Build, Ship and Run Any App, Anywhere”.

Beside Docker, the session continued with introducing the audience to microservices and various platforms for enabling container approach like:
OpenShift, an open-source Platform developed by RedHat which acts as a PaaS (Platform-as-a-Service),
Fabric8, an integrated open-source DevOps and Integration Platform and which provides Continuous Delivery, Management and ChatOps features,
Kubernetes, an open-source platform developed by Google for automating deployment, scaling, and operations of application containers across clusters of hosts
This presentation ended with a real live demo of creating a new project on Fabric8 platform. The new project was a simple Java EE application based on Apache Camel framework. Nothing fancy but it demonstrated that environment for a Java application could be set up and ready for further development in a minute without any big prerequisite knowledge.


The event succeeded to join below the same roof lots of heterogeneous attendees and speakers in quality. It was a well organized and definitely worth-to-visit conference. Most common thing for all of them was, of course Java – come on, it’s the 20th anniversary of Java anyway. But my personal impression was that most used buzzwords at the conference were:

  • Internet of Things,
  • Microservices, API,
  • Containers, DevOps,
  • Cloud computing.

It wouldn’t be fair not to mention some other interesting topics from the conference such as Big Data and NoSQL, Reactive programming, Graph Databases, new features of Java 8 EE, Spring 4.2, Scala and many, many others.
Organizers of the event recorded every session and also provided a live stream which is now accessible over conference’s official YouTube channel.

Definitely, see you again on Voxxed Days next year 😉