Foojay.io, the Friends Of OpenJDK!

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