Devoxx Belgium 2023 – AMIS Technology Blog | Oracle

At the beginning of this month, I attended the Devoxx Belgium 2023 event in Antwerp. And there was something to celebrate because it was the 20th edition.

In this article I gathered some practical information about the event, and the sessions that were held. Perhaps this gives you more insight in what you can expect from such an event and it may help you in deciding if, as it was for me, such an event is an opportunity for you to gather/share information. For me, this was the fourth Devoxx event I attended.

I would say that the main focus of this year’s event was Java 21 and of course Artificial intelligence (AI).

For more information, please see:

Devoxx Belgium

Devoxx Belgium is a 5-day conference (from Monday October 2nd until Friday the 6th 2023), where developers come together to explore the latest technology advancements and fascinating ideas, with some of the most inspiring speakers in our sector.

Attending Devoxx Belgium presents a remarkable opportunity to broaden your knowledge, refine your skills, and gain firsthand experience with the most recent technologies, particularly in the ever-evolving fields of AI and Java.

There were more than 3000 attendees and about 200 speakers.

Each year the Devoxx Family welcomes over 20,000 developers to events in Belgium, France, UK, Poland, Morocco, Greece & Ukraine and additional VoxxedDays cities around the globe.


With regard to tickets, the following options were available:

  • Combi ticket (2 – 6 Oct) = 975 Euro *
  • Conference ticket (4 – 6 Oct) = 650 Euro *
  • Deep-Dive ticket (2 – 3 Oct) = 400 Euro *

* + 21% VAT

Please be aware that this event sold out in a matter of seconds.

Different kind of sessions

During the 5 days Devoxx Belgium 2023 event different kind of sessions were held with a specific time period:

Inspiring and thought provoking, 20 minute keynotes open the conference, with a 45 minute keynote that rounds us out.

3 hour sessions where attendees can rapidly immerse themselves in a subject matter with an in-depth examination of a topic or technology.

2 or 3 hour hands-on sessions where you delve into a specific technology or methodology under expert guidance.

50 minute tech sessions on a range of different technologies, practices and methodologies.

45 minute lunchtime sessions on a range of different technologies, practices and methodologies.

30 minute sessions focused on demonstrating technical tools or solutions.

Informal sessions of one hour, where like minded people get together and discuss technology.


Content tracks

The sessions can be divided into the following content tracks:

Devoxx Belgium 2023 lameriks 2023 10 2 Java
All aspects of Java as a platform: emerging or established, Java language, JVM (languages), JDK, frameworks, standards, performance etc.
Devoxx Belgium 2023 lameriks 2023 10 3 Server Side Java
Frameworks and libraries which are mainly used on the server-side: Spring, Jakarta EE, Reactive frameworks, ORM, MOM, DB, Micro-services frameworks, Quarkus/Micronaut etc.
Devoxx Belgium 2023 lameriks 2023 10 4 People & Culture
Personal development, leadership, working practices, mental health, diversity, inclusion and developer culture.
Devoxx Belgium 2023 lameriks 2023 10 5 Build & Deploy
Modern operational concerns, including build pipelines, orchestration, observability, monitoring, resilience, and compliance, as the software world embraces DevOps and cloud delivery.
Devoxx Belgium 2023 lameriks 2023 10 6 Architecture
How-to’s, tools and techniques for developers to drive great architectures. Share your in-the-trenches experiences informing us what works and what doesn’t.
Devoxx Belgium 2023 lameriks 2023 10 7 UI & UX
UI, UX, front-end languages, frameworks and architectures. This can include Angular, React, VUE, Blazor, SCSS best practices etc.
Devoxx Belgium 2023 lameriks 2023 10 8 Data & AI
Big Data, Fast Data, NoSQL, Machine learning, Deep Learning, Neural Networks, TensorFlow, Large Language Models, Transformers, etc.
Devoxx Belgium 2023 lameriks 2023 10 9 Development Practices
All about Getting Stuff Done right. Methodologies, better practices, testing & tools.
Devoxx Belgium 2023 lameriks 2023 10 10 Security
Encryption, defensive practices, tools and technologies to be secure, security testing etc.
Devoxx Belgium 2023 lameriks 2023 10 11 Mind the Geek
Developer candy: stuff we want to know about but don’t (generally) do at work – robotics, biological computing, cybernetics, AI, new toys & tomorrows world.


Mobile schedule

Of course, in advance of the event the schedule is already available for your mobile device, with detailed information about the content of each session.
Devoxx Belgium 2023 lameriks 2023 10 12


Desktop schedule

And for your desktop, also in advance of the event the schedule is already available.

Devoxx Belgium 2023 lameriks 2023 10 13


For me, the schedule with all the sessions was very helpful. Being able to see in advance which sessions were the most favorite, helped me in some cases to decide to which sessions I wanted to go.

To make your choice easier, the talks are also grouped by track.

Devoxx Belgium 2023 lameriks 2023 10 14

Number of talks per track:

  • Architecture:    12
  • Build & Deploy:    18
  • Data & AI:    27
  • Development Practices:    35
  • Java:    38
  • Mind the Geek:    12
  • People & Culture:    18
  • Security:    12
  • Server Side Java:    25
  • UI & UX:    14

Sponsors and booths

In the exhibition hall many sponsors have booths were you can see there products, ask questions, etc.

Devoxx Belgium 2023 lameriks 2023 10 15

Please see the website for the complete list of all sponsors.

Voice to text

This year for every session, everything the speaker said, in real time was visible as text at the bottom of the cinema screen.

Devoxx Belgium 2023 lameriks 2023 10 16

On the picture of the demo about the work in progress AI Assistant for IntelliJ IDEA by Anton Arhipov from JetBrains, you can see what he (more or less) said at that moment:

… plugin and I can ask it to explain. The code. It’s gonna collect the context. It’s, it analyzes the code. So it sees the dependenci …

Information about the sessions

All sessions are recorded and are already available on the YouTube channel:

Here is for example the link to the keynote “20th edition of Devoxx Belgium” by Stephan Janssen (also known as mister Devoxx 😊):

For every session, the link to the recording is also easy to find from the schedule.

Important news/sessions at Devoxx

I leave it up to you to have a look at the sessions that were held and that may be interesting to you to have a look at.

I would say that the main focus of this year’s event was Java 21 and of course Artificial intelligence (AI).

During the event the Top Rated Talks of the Week are constantly updated and presented. Here you see the status at Friday 6th October 11:30 am (CEST).

Devoxx Belgium 2023 lameriks 2023 10 17

However, I will share with you a few sessions I visited. And because there was recently news about the latest Java version, I will focus on that topic first.

Some example sessions related to Java 21

Here are some example session related to Java 21:

As you can see, this year, James Gosling (best known as the founder and lead designer behind the Java programming language), was also one of the speakers.

Devoxx Belgium 2023 lameriks 2023 10 18


Java 21, by Brian Goetz (Oracle)

Oracle recently announced the availability of Java 21, the latest version of the world’s number one programming language and development platform. Oracle will offer long term support for Java 21 for at least eight years.

Devoxx Belgium 2023 lameriks 2023 10 19

In the picture above, from the keynote from Brian Goetz (Oracle), you can see the list of JDK Enhancement Proposals (JEPs) that are in Java 21, related to:

  • Language and tooling
  • Performance and Runtime
  • Libraries
  • Stewardship and housekeeping

For more information, please see for example the Press Release “Oracle Releases Java 21 and Extends Support Roadmap”

Or watch the keynote from Brian.

Large Language Models (LLM)

Devoxx Belgium 2023 lameriks 2023 10 20

Stephan Janssen, in his “20th edition of Devoxx Belgium” keynote, talked about Large Language Models (LLM) and how since the release of ChatGPT (by OpenAI) in November last year, our lives have changed. We are now seeing these other large language models. In the beginning the context window was about 4k in size, now it is already 32, 64 and even 100k.

See for more information:

Sessions related to Large Language Models (LLM) and Artificial intelligence (AI)

Here are the sessions related to Large Language Models (LLM) and Artificial intelligence (AI):

  • Challenges and benefits of coding with generative AI, by Laurent Doguin
  • From Clicks to Conversations: Designing LLM-powered Apps, by Marie-Alice Blete
  • Generative AI in practice: Concrete LLM use cases in Java, with the PaLM API, by Guillaume Laforge
  • How generative AI brings synthetic data to software engineering, by Wim Blommaert
  • How to build a GPT4All, by Andriy Mulyar
  • Human vs AI: How to ship secure code, by Joseph Katsioloudes
  • Introduction To Building AI Applications: LangChain 101, by Greg Kamradt
  • Java Meets AI: A Hands-On Guide to Building LLM-Powered Applications with LangChain4j, byLize Raes
  • JetBrains AI: A Deep Dive, by Vladislav Tankov
  • Lessons Learned Building a GenAI Powered App, by Marc Cohen
  • Lessons learned using Machine Learning in Java, by Jago de Vreede
  • Making your @Beans Intelligent, by Mark Pollack
  • ML in Java, YES it’s possible! , by Mohammed Aboullaite
  • MLOps: Keeping models from misbehaving like angry teenagers, by Cedric De Haes Bert Gossey
  • Optimize the world for fun and profit, by Geoffrey De Smet Lukáš Petrovický
  • Performance and Scale – Domain-Oriented Objects vs Tabular Data Structures, by Rustam Mehmandarov Donald Raab
  • PostgreSQL, The Time-Series Database You Actually Want, by Christoph Engelbert
  • Rubber Grokking: Enhancing Software Development with AI, by Remo Dentato
  • Semantic Kernel: AI orchestration for intelligent apps, by John Oliver Bruno Borges
  • State of the Art of Generative AI, by Natalie Pistunovich
  • The Art of Questions: Creating a Semantic Search-Based Question-Answering System with LLMs, by Jettro Coenradie Daniël Spee
  • The battle of the AI coding assistants, by Bouke Nijhuis
  • Understanding Probabilistic Data Structures with 112,092 UFO Sightings, by Guy Royse

Please see the schedule for more information and the link to the recordings.

Devoxx Belgium 2023 lameriks 2023 10 21

AI Assistant, by Anton Arhipov (JetBrains)

Anton showed a small but impressive demo that demonstrated most of the features of the plugin (at the state of the week before) in regard to working with some existing code or making sense of existing code (as opposed to generating new code). For example, in his sample code (public class TheAlgorithm), via Alt+Enter he selected the AI Actions menu and started the action “Explain TheAlgorithm class”.

Devoxx Belgium 2023 lameriks 2023 10 22

This action is going to collect the context. It analyses the code. So it sees the dependencies that are used in that specific part of the code and where it’s used. From the response from the backend service you could see it really knows the algorithm and it explains piece by piece what the code does.

Devoxx Belgium 2023 lameriks 2023 10 23

Then Anton showed how, in a snippet of code, the AI assistant can now suggest a better name for a particular method, since it now knows the domain specifics of this TheAlgorithm class.

Here is a list of the AI Actions menu:

  • Write documentation
  • Explain <some> class
  • Suggest refactoring
  • Generate code
  • Find problems in selection
  • New Chat Using Selection
  • Add your prompts


Of course I only mentioned a small part of his demo. So, please see the recording. And for even more information, please see:

Stephan Janssen in his keynote told that he asked JetBrains to do a demo of the (work in progress) AI Assistant plugin for IntelliJ IDEA. For all fairness he said, he also could have asked Amazon CodeWhisperer
[] or GitHub Copilot [].

I you are interested int his topic, see for example also the following session:
“Boost Your Coding Productivity: Embrace the AI code assistance with GitHub Copilot and Amazon CodeWhisperer”, by Piyush Mundada (Cognizant/ING Belgium).

How sand and Java are used to create the world’s most powerful chips, by Johan Janssen (ASML)

If you want to know more about some mind boggling piece of (lithography) machinery, from the Dutch company ASML, I can recommend this session.

In this session Johan Janssen (ASML) explains how computer chips are physically created by some of the most advanced machines on the planet. Did you know that these chips, nowadays, can contain more than one hundred million transistors per square millimeter?

Devoxx Belgium 2023 lameriks 2023 10 24

ASML is working on a relatively new analytics platform which is used to process the data from the machines. The application then visualizes the results in order to find issues or improvement areas. This information is used to change the configuration parameters of the physical machine in order to create more and better chips. In this session Johan explained, on a high level, how their applications look like and which Java technologies they use to create better chips, with transistors that are at the moment about 3 nanometer in size. And to put this in perspective, one million nanometer is one millimeter !

Devoxx Belgium 2023 lameriks 2023 10 25


Devoxx events in 2024

If you are interested in attending a future Devoxx event, please see for more information. Here are some examples:


Attending Devoxx Belgium, was great for me in gaining new insights and knowledge on a variety of subjects, in particular Java 21, Large Language Models (LLM) and Artificial intelligence (AI).

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