Every year, when we start planning JCON EUROPE, one question always guides us:
How do we create a conference that developers genuinely enjoy attending?
Not just another event with slides and sponsor booths. Not a place where people passively consume information and leave. We wanted to create an environment where developers actively connect, discuss, challenge ideas, and solve real-world problems together.
Looking back at JCON EUROPE 2026, I believe this spirit was visible everywhere.
From April 20 to 23, more than 1,000 developers from over 60 countries came together at the Cinedom cinema complex in Cologne to exchange ideas around Java, AI, cloud-native architectures, software modernization, developer tools, and the future of our ecosystem.
And despite all the changes in our industry, one thing became very clear once again:
In-person community still matters.
Why the Venue Matters
One of the most distinctive aspects of JCON remains the cinema venue itself.
At first glance, hosting a software conference in a multiplex cinema sounds unusual. But once you experience live coding on a massive cinema screen, the idea immediately makes sense.
Complex code examples remain readable even from the back rows. Architecture diagrams become easier to follow. And during debugging sessions or deep technical explanations, attendees can actually follow along without struggling to read tiny fonts on overloaded presentation slides.
As organizers, we often hear attendees mention that this changes the entire learning experience. It creates a stronger sense of focus and immersion than traditional conference rooms.
And Java developers appreciate details.
The Real Conference Happens Between the Talks
Of course, JCON had more than 100 sessions, over 100 speakers, and workshops covering everything from OpenJDK internals to AI-assisted development.
But if you ask me what makes JCON special, the answer is simple:
The hallway track.
Some of the most valuable moments at JCON never appear on the official schedule. They happen after a session ends, when small groups form in the hallways and conversations continue naturally.
Someone asks a follow-up question.
Another developer explains how they solved a similar issue in production.
A framework maintainer suddenly joins the discussion.
Five minutes later, what started as a quick chat turns into a practical architecture discussion with direct relevance to somebody’s daily work.
This is difficult to reproduce online. It cannot really be streamed. And it is one of the main reasons why physical conferences remain highly relevant in 2026.
One of my favorite pieces of feedback this year came from Adam Bien:
“How do you measure the greatness of a conference? I arrived here, tried to walk around this small circle and it took me 3 hours, since I had so many nice people approaching me with interesting conversations.”
I think this perfectly captures what makes JCON special. The value of the conference is not only measured by the sessions on the schedule, but by the spontaneous discussions, the reconnecting with old friends, and the unexpected conversations that turn into new ideas, collaborations, or sometimes even solutions to real production problems.
AI Was Everywhere – But in a Pragmatic Way
Artificial Intelligence was naturally one of the major themes at this year’s conference.
With the new Premium AI Track, we wanted to approach the topic from a practical Java developer perspective instead of simply following industry hype.
The discussions focused on questions developers are actually facing today:
- How can AI improve developer productivity without creating dependency?
- Which models can realistically run locally?
- How do organizations handle privacy-sensitive environments?
- What does AI integration look like inside existing enterprise Java systems?
- How do teams maintain control over architecture and maintainability?
The interesting part was that the conversations were far more nuanced than a year ago.
The industry is slowly moving beyond simplistic “AI replaces developers” narratives. Instead, teams are beginning to understand where AI genuinely helps and where engineering experience still matters enormously.
Another highlight around the AI track was the presentation of the AI Sustainability Award by the eco Verband der Internetwirtschaft e.V. and KI Bundesverband to Dell Technologies and Cyrock.AI.
The award recognized a remarkable engineering achievement focused on one of the biggest challenges in modern AI infrastructure: energy consumption.
The companies demonstrated an architecture capable of reducing compute resources, energy usage, and CO2 emissions for generative AI workloads by up to 80 percent. Particularly interesting for many attendees was the pragmatic engineering approach behind it: instead of relying on permanently running monolithic systems, the platform uses highly modular compute units that are only active when actually needed.
The discussions around this award showed that the future of AI will not only be defined by model capabilities, but also by efficiency, sustainability, and the ability to operate powerful AI systems responsibly at scale.
The Java Ecosystem Continues to Evolve
One thing that always stands out at JCON is how broad and healthy the Java ecosystem remains.
You meet contributors from OpenJDK, maintainers from Apache Maven, experts from Quarkus, Jakarta EE, Vaadin, Testcontainers, Spring, AI tooling vendors, cloud providers, and many more.
And perhaps most importantly, these people are approachable.
One of the strengths of the Java community has always been its openness. Junior developers can walk up to highly experienced engineers and simply start a conversation.
That culture still exists.
This year also showed how strongly companies continue to invest in Java.
IBM presented “IBM Bob,” their new AI-supported developer platform. Microsoft expanded its Java community engagement further. Companies like Azul, JetBrains, Moderne, and many others actively contributed to discussions around tooling, modernization, observability, and developer productivity.
The ecosystem is evolving quickly, but Java continues to provide something extremely valuable:
Stability combined with continuous innovation.
Community Is Still the Foundation
One of the most rewarding aspects of organizing JCON is seeing how international the event has become.
Developers from more than 60 countries attended this year.
Different industries. Different cultures. Different architectural challenges.
But once conversations begin, everybody speaks the same technical language.
That creates a very special atmosphere.
You quickly realize that many teams around the world struggle with similar questions:
- How do we modernize legacy systems safely?
- How do we adopt AI responsibly?
- How do we keep systems maintainable over decades?
- How do we help younger developers grow?
These discussions create perspective. And often, they create friendships as well.
As organizers, that is ultimately what we try to build:
A conference where technology matters, but people matter even more.
One moment that reflected this spirit particularly well was the presentation of the Java Community Leadership Award to Sharat Chander. The award recognized 25 years of passion, leadership, and commitment to the global Java community.
Over the years, Sharat has played an important role in connecting developers, companies, user groups, and technology leaders across the ecosystem while continuously supporting and encouraging new generations of developers.
Honoring him at JCON felt very fitting because the conference itself is built around many of the same ideas: openness, mentorship, collaboration, and long-term community engagement.
Looking Ahead to JCON EUROPE 2027
Planning for the next edition already started while this year’s conference was still running.
JCON EUROPE 2027 will take place from April 26th to 29th in Cologne.
The challenge now is not simply to grow larger. The challenge is preserving the atmosphere that makes JCON valuable in the first place.
As AI accelerates software development and remote work continues reshaping collaboration, I believe conferences like JCON become even more important. Not because information is unavailable online. But because trust, collaboration, mentorship, and real technical exchange still happen best face to face.
The Java ecosystem has always been unusually community-driven. JCON exists because thousands of people actively contribute knowledge, organize meetups, mentor newcomers, build tools, maintain frameworks, and help each other improve. That spirit was visible everywhere in Cologne this year. And honestly, seeing that gives me a lot of optimism for where Java is heading next.
More impressions and photos from JCON EUROPE 2026 are available on Flickr!
