Utrecht JUG Meetup – Nov 11: Java Security & Agentic AI in Legacy Modernization
Details
We’re excited to welcome you to Utrecht JUG on November 11th, hosted by PSG Technauts. Join us for an evening full of Java, AI, software architecture, practical insights, great conversations, food, drinks, and plenty of opportunities to connect with fellow developers.
We’ll start the evening with food and drinks before diving into our first session, where Ana Maria Mihalceanu, Java Champion Alumni and Certified Architect, explores the future of Java security in the age of quantum computing. From Hybrid Public Key Encryption (HPKE) to post-quantum hybrid key exchange in TLS 1.3, Ana will demonstrate how Java developers can prepare their applications for emerging security challenges, using `keytool` to manage keys and certificates and JDK Flight Recorder (JFR) to inspect security details at runtime.
After the break, Marek Dominiak, CTO, architect, tech lead, and IT trainer, takes us behind the scenes of modernizing a Java monolith with more than two million lines of code using agentic AI. What happens when AI agents help rewrite a critical legacy feature, the initial checks look promising, but the first production release fails? Marek shares what went wrong, how the team recovered, and how the lessons learned led to a third version that finally worked in production. He’ll explore where AI agents saved time, where they went off track, and how disciplined engineering practices made the difference between a failed release and a successful modernization.
Whether you’re interested in the future of Java security or the practical realities of using agentic AI to modernize legacy systems, this meetup offers plenty of insights to take back to your own projects.
Please join us and RSVP!
Because of the limited number of seats, please keep your RSVP up-to-date, so we can welcome someone else if you can't make it.
***
## Timeschedule
17:30 Doors open
18:00 Food & Drinks
18:45 Modern Java Security in the Age of Quantum Computing — Ana Maria Mihalceanu
19:45 Break
20:00 Modernizing a 2M+ LOC Java Monolith with Agentic AI: What Worked, What Failed, and How We Recovered — Marek Dominiak
21:00 Drinks
***
## Talks
### Securing Java for the Quantum Era
Most Java applications rely on cryptography every day, often without much thought, because we trust the algorithms underneath. But as computational power advances, how much of that trust will hold up?
The risks aren't far off. Encrypted data captured today could be decrypted years from now, putting greater pressure on how we secure applications today.
In this session, we'll explore modern Java security, from the concepts behind Hybrid Public Key Encryption (HPKE) to a hands-on demo of post-quantum hybrid key exchange in TLS 1.3, using keytool to manage keys and certificates and JDK Flight Recorder (JFR) to inspect security details at runtime
### Modernizing a 2M+ LOC Java Monolith with Agentic AI: What Worked, What Failed, and How We Recovered
Modernizing a 2M+ line Java monolith meant much more than upgrading Java, Spring, Hibernate, and Elasticsearch. We also had to deal with tightly coupled dependencies, abandoned libraries, outdated patterns, and features that had been too risky to change for years.
This talk focuses on one of them: a critical indexing feature that needed to be rewritten to improve performance, fairness, and maintainability.
I'll show how we used agentic AI to analyse the legacy implementation, divide the work into manageable loops, and build a new version. It looked promising and passed our initial checks, but the first production release failed.
I'll explain what went wrong, how we recovered, and how the lessons from versions one and two led to a third version that finally worked in production.
You'll also see the engineering safeguards that made this possible: controlled context, clear instructions, automated tests, review, monitoring, rollback, security checks, and an explicit definition of done.
This is not a story about AI magically fixing legacy code. It is a practical case study about where agents saved time, where they drifted, and how disciplined engineering turned a failed release into a successful modernization.
***
## Speakers
### Ana Maria Mihalceanu
####
Ana is a Java Champion Alumni and Senior Developer Advocate for the Java Platform Group at Oracle, with an extensive background in Java and cloud development. More recently, her work has expanded to explore how machine learning and AI can be applied within the Java ecosystem, helping Java developers adopt emerging capabilities while continuing to benefit from the stability, tooling, and performance of the Java Platform. She actively supports the growth of technical communities through knowledge sharing and enjoys curating content for conferences as a program committee member.
### Marek Dominiak
####
I’m a CTO of Sparkbyte Solutions, co-owner of Trainitek, and an architect and tech lead at Mintra. I have 19 years of experience, mainly in the Java world. I’ve spent a lot of time mentoring developers and leading teams, with a big focus on creating solutions that will actually last for many years. That got me into Software Craftsmanship, Domain-Driven Design, and code quality early on.
Over my career, I’ve completed many small and large projects that run in production, interviewed developers, handled communication with customers, designed architecture for entire systems and delivered them, and introduced many technologies proven in production. I have 15 years of experience working in the Scandinavian market.
I’ve trained over 700 people in modern architecture, Domain-Driven Design, EventStorming, and testing, and regularly speak at software development conferences.