What turns a nervous first-timer into a confident conference speaker? Let's find out.

This the last Foojay Podcast of 2025 and also the last one with interviews recorded at the Devoxx and JFall conferences. Maybe you're already thinking about your goals for 2026: organizing a meetup, submitting your first conference talk, or taking a bigger role in the Java community. If that sounds like you, this episode is for you.

I talked with the people behind these conferences and developers at different stages of their speaking journey. At Devoxx, I spoke with Stephan Janssen, who has been organizing Devoxx for 20 years, Susanne Pieterse, about what makes conferences valuable for learning, and Daniël Floor, a developer just starting out with public speaking. At JFall, I caught up with organizers Martin Smelt and Brian Vermeer, Berwout de Vries Robles, who coaches new speakers, and Annelore Egger about her journey from developer to conference speaker.

You'll hear practical advice about what makes a good CFP, why conference organizers actively want new speakers, and how the Java community is set up to help you get started. Whether you're thinking about submitting your first talk or curious about what goes into organizing a conference, there's something here for you.

00:00 Introduction of topic and guests

01:33 Stephan Janssen

• https://www.linkedin.com/in/stephanjanssen/
• Devoxx Organizer

07:03 Martin Smelt

• https://www.linkedin.com/in/martin-paul-smelt-8b699a8/
• JFall Organizer

13:27 Brian Vermeer

• https://www.linkedin.com/in/brianvermeer/
• JFall Organizer and speaker
• Tips for speakers, writing a CFP
• Join a JUG!

21:02 Annelore Egger

• https://www.linkedin.com/in/anneloredev/
• How to become a speaker

27:43 Daniël Floor

• https://www.linkedin.com/in/dani%C3%ABl-floor-266652208/
• Taking the first steps into public speaking
• Finding your speaking topic

31:28 Berwout de Vries Robles

• https://www.linkedin.com/in/berwout-de-vries-robles/
• Tips for speakers
• Propose a talk to speak at a JUG

37:08 Susanne Pieterse

• https://www.linkedin.com/in/susannepieterse/
• Learning at conferences, RAG, and other topics
• Meeting and talking to the presenters and specialists at a conference
• CO-organizer of ML Con and DevOpsCon in Amsterdam
• https://mlconference.ai/
• https://devopscon.io/amsterdam/

41:20 Conclusion

What if work-life balance is a myth, and the real secret is just... life?

In this Foojay Podcast we're stepping away from pure code and diving into something equally important: how we live our lives as developers. Because let's be honest, being a great programmer isn't just about mastering Java or the latest framework. It's about managing your career, your health, your family, and finding purpose in all of it.

Four incredible guests are all tackling different pieces of this puzzle. First up, Bruno Souza, the Brazilian Java Man, is back to challenge our thinking about work-life balance and share his philosophy on taking control of your career. Then Patricia Lenten talks about the real challenges of hacking parenting while being an engineer, and how we can inspire the next generation of developers. Georgios Diamantopoulos brings the hard data on why sitting is literally killing us and what we can actually do about it. And finally, April Schuppel shares lessons from Apryse's journey through 15 acquisitions in five years—and why people, not AI, are still the most important part of building great products.

00:00 Introduction of topic and guests

01:20 Bruno Souza

• https://www.linkedin.com/in/brjavaman/
• Grow your career podcast: https://foojay.io/today/foojay-podcast-72/
• Bruno's YouTube channel: https://www.youtube.com/@brjavaman
• Work-life balance doesn't exist, we only have life

12:52 Patricia Lenten

• https://www.linkedin.com/in/patricialenten/
• Hacking your parenting
• Technology is fun

18:37 Georgios Diamantopoulos

• https://www.linkedin.com/in/georgiosd/
• Staying Healthy
• The importance of getting out of your chair
• https://stateofhealth.tech/

22:58 April Schuppel

• https://www.linkedin.com/in/aprilschuppel/
• Pull, Push, and Merge: Lessons from a Journey of Growth Through Acquisitions
• The people are the most crucial part to build a team, product, and company

30:26 Outro

The AI revolution isn't replacing Java developers. No, it's forcing us to think harder.

Welcome to another episode of the Foojay Podcast! Today, we're talking about AI and Java, how it's changing the way we work, what we need to watch out for, and why understanding what's really happening matters more than ever.

I recorded interviews at Devoxx and JFall and spoke with people who build and use this technology every day.

Marianne Hoornenborg opened my eyes to something important: every time an AI generates a token, there's a massive amount of computation happening behind the scenes.

Viktor Gamov and Baruch Sadogursky did something really cool: they tested six different AI coding tools live on stage with the same task. The results were all over the place! But they found that the tools with access to good documentation performed much better.

Stephen Chin showed me how graph databases can make AI responses more reliable by providing a solid source of truth rather than relying on vector search.

Mario Fusco works on LangChain4J, a leading Java framework for AI. He explained that breaking down large tasks into smaller ones and using specialized agents can help reduce errors—hallucinations, as they're called.

Jeroen Benckhuijsen and Martijn Dashorst shared their experiences working with enterprise Java. Even as frameworks are becoming lighter and we're running everything in containers, there are still complex problems that require real developer expertise.

Maarten Mulders reminds us that AI is a tool, not a replacement—especially when you're solving problems no one has tackled before. You still need to know what you're doing.

And finally, Simon Maple from Tessel discussed moving beyond vibe coding towards a more reliable, production-ready approach, using specifications to guide AI tools.

00:00 Introduction of topics and guests

02:12 Marianne Hoornenborg

• https://www.linkedin.com/in/mhoornenborg/
• The Simple Math behind AI
• The cost of tokens when using LLMs

06:54 Viktor Gamov and Baruch Sadogursky

• https://www.linkedin.com/in/vikgamov/
• https://www.linkedin.com/in/jbaruch/
• Robocoders, about the many agentic tools that can be used for vibe coding
• https://context7.com/

16:24 Stephen Chin

• https://www.linkedin.com/in/steveonjava/
• Graph versus relational databases
• Explaining MCP and Agents

23:09 Mario Fusco

• https://www.linkedin.com/in/mario-fusco-3467213/
• AI and LangChain4j in Quarkus
• Coding tools with AI

35:43 Jeroen Benckhuijsen

• https://www.linkedin.com/in/jeroenbenckhuijsen/
• Java in business, Evolutions in Java
• Making use of containers and Kubernetes
• Learning from the community

41:44 Martijn Dashorst

• https://www.linkedin.com/in/dashorst/
• Investigating an OOM-killer in Kubernetes with the help of AI

49:37 Maarten Mulders

• https://www.linkedin.com/in/mthmulders/
• How AI may impact our jobs
• How to improve your Maven builds

56:13 Simon Maple

• https://www.linkedin.com/in/simonmaple/
• AI developer tool Tessl
• Spec-driven vibe coding
• Secure AI development

01:02:12 Conclusion

Episode 85 of the Foojay Podcast. All info, show notes, and links are available at https://foojay.io/today/category/podcast/.

What if the future of Java depends on who we invite to learn it today?

In this Foojay Podcast, we're diving into something that affects all of us in the Java community: How can we inspire the next generation of developers, and how do we make the developer world more inclusive?

You'll hear four incredible guests who are actively working to make tech more accessible and inclusive. First, Daniel De Luca talks about Devoxx for Kids and how they support underprivileged students in IT education. Then Kenny Schwegler shares his insights on how we can actively promote diversity and inclusion in tech. Cassandra Chin, the youngest Java Champion and author, talks about inspiring young coders through hands-on projects and making technology fun. And finally, Igor De Souza discusses his mission to bring Java into Raspberry Pi education and bring more Java into coding clubs worldwide.

These conversations share one message: Talent is everywhere, but opportunity isn't. And we have the power to change that!

01:19 Daniel De Luca

• https://www.linkedin.com/in/danieldeluca/
• Founder Devoxx4Kids
• Activities of Devoxx4Kids
• How to inspire children of all ages to get interested in technology

14:24 Kenny Schwegler

• https://www.linkedin.com/in/kenny-baas/
• How to build inclusive, diverse teams
• How the IT industry became male-focused because of IBM marketing
• Books:
• https://www.manning.com/books/collaborative-software-design
• https://learningsystemsthinking.com/

26:07 Cassandra Chin

• https://www.linkedin.com/in/cassandra-chin-developer/
• Inspiring children and parents into technology
• Fun projects to introduce engineering to children
• Book:
• https://www.amazon.nl/Raising-Young-Coders-Teaching-Programming/dp/B0DVBQZ483
• 20% Discount code on the Springer website "APAUT"
• https://link.springer.com/book/10.1007/979-8-8688-1393-1

32:45 Igor De Souza

• https://www.linkedin.com/in/igfasouza/
• Java in code clubs like CoderDojo
• Java in space
• Collecting Java tutorials and courses for children
• Java Catalog on Foojay GitHub
• https://github.com/foojayio/java-education-catalog
• Pi4J library
• https://www.pi4j.com/
• HelloWorld magazine:
• https://downloads.ctfassets.net/oshmmv7kdjgm/6jGvFLH86Ems5AJR84Krsk/3888c571ddc1543c9cdb01ce5eff616d/HelloWorld28.pdf

55:27 Conclusions

In this Foojay Podcast, we're exploring a critical topic that's becoming increasingly important in our industry: developing sustainable software that is both performant and environmentally friendly.

At the Devoxx and JFall conferences, I had fascinating conversations about how we as Java developers can make a real impact on both our cloud costs and our carbon footprint. And it's interesting to learn how these two goals are often perfectly aligned: what's good for your budget is usually good for the planet too.

We start with Daniel Witkowski. He published an article on Foojay that takes us on a deep dive into performance tuning. He explains why optimizing your code can have a thousand times more impact than saving 30% on cloud costs, and walks us through his journey of turning a simple integer validation challenge into a masterclass on Java performance optimization.

Next, I caught up with Ko Turk, who shares his passion for sustainable engineering and space exploration. He introduces us to Kepler, a tool for monitoring the energy consumption of your applications, and explains how performance optimization naturally leads to sustainability improvements.

Then Ronald Dehuysser, founder of JobRunr, reveals how his open-source job-scheduling library now enables carbon-aware job processing. He explains how JobRunr can automatically schedule non-time-critical jobs to run when renewable energy is most available.

And finally, Jan Ouwens joins us to discuss practical strategies for reducing both costs and CO2 emissions in your applications. He explains why cloud spending is actually a good proxy for your carbon footprint.

00:00 Introduction of topic and guests

02:07 Daniel Witkowski

• https://www.linkedin.com/in/danielwitkowski
• https://foojay.io/today/the-art-of-performance-tuning-why-saving-30-in-the-cloud-means-nothing-if-your-code-wastes-1000x-more/
• https://foojay.io/today/foojay-podcast-83/
• Why Saving 30% in the Cloud Means Nothing if Your Code Wastes 1000× More
• Performance tuning is less about syntax and more about craftsmanship.

29:46 Ko Turk

• https://www.linkedin.com/in/ko-turk-b271b929/
• https://github.com/sustainable-computing-io/kepler
• Sustainable engineering
• Kubernetes Efficient Power Level Exporter (Kepler)

32:46 Ronald Dehuysser

• https://www.linkedin.com/in/ronalddehuysser/
• https://www.jobrunr.io/en/
• Carbon-aware job processing with JobRunr
• Growing from an open-source project to a company

37:36 Jan Ouwens

• https://www.linkedin.com/in/janouwens/
• https://jqno.nl/
• Reducing the cost and CO2-emissions of your application
• Private cloud versus cloud providers

45:14 Outro

In this Foojay Podcast, we're diving deep into some of the most exciting developments happening within the OpenJDK and TornadoVM projects.

At the Devoxx and JFall conferences, we spoke with several speakers and visitors about some of the major themes that are shaping the future of Java development. The first guest is Moritz Halbritter from the Spring Engineering team. He provides us with more insights into Project Leyden and how it's improving Java startup times through ahead-of-time compilation and profiling. We'll learn how Spring Boot developers can already take advantage of these improvements today.

Next, we'll hear from John Cecerralli at Azul about performance optimizations, the evolution from x86 to ARM64 architectures, and how OpenJDK Projects bring improvements to the JVM itself at levels we couldn't achieve before.

Then, Balkrishna Rawool will guide us through the world of vector databases and explain how Java's Vector API from Project Panama is perfectly positioned for AI use cases, despite its development beginning years before the current AI boom.

And finally, we'll meet some of the team members behind TornadoVM - Christos Kotselidis and Michalis Papadimitriou from the University of Manchester - who will explain to us how Java developers can now harness the power of GPUs for AI workloads, running large language models in pure Java without leaving the Java ecosystem. They also explain the connection between TornadoVM and the OpenJDK Project Babylon.

00:00 Introduction of topics and guests

01:58 Moritz Halbritter

* https://www.linkedin.com/in/moritz-halbritter-9301a1b1/

* Project Leyden and how it can already be used with Spring

* Difference between the approach of Project Leyden and CRaC

11:02 John Cecerralli

* https://www.linkedin.com/in/john-ceccarelli-95b7041/

* OpenJDK evolutions in Project Leyden

* Startup time improvements in Azul Prime

* Java performance

* ARM Graviton

17:08 Balkrishna Rawool

* https://www.linkedin.com/in/balkrishnarawool/

* Vector API, project Panama

22:44 Christos Kotselidis, Michalis Papadimitriou

* https://www.linkedin.com/in/michalis-papadimitriou/

* https://www.linkedin.com/in/kotselidis/

* https://www.tornadovm.org/

* https://www.tornadovm.org/gpullama3

* https://github.com/beehive-lab/TornadoVM

* TornadoVM status update, Java on GPU

* How TornadoVM relates to Project Babylon and Project Panama

33:42 Outro