Warmed up Java
❗❗ EVENT IS HELD IN-PERSON ONLY, IN PRAGUE ❗❗
We're back with more Java topics, continuing to ride the fast Java wave! This time, our main speaker Michal Karm will dive into the world of Ahead-of-Time compilation at the CEZ offices in Prague. For our partner talk, Mojmír Nebel from CEZ will share the highs and lows of building a new IT team.
Talk 1:
🎤 "Businesss story: From legacy to Java and back" - by Mojmir Nebel, CEZ
Imagine there’s no IT — only business people in the clouds…
It sounds like the beginning of a protest song, so it’s hard to believe this could ever be a real scenario in a large corporation. But that’s exactly where we found ourselves. We had to build a completely new architecture from scratch — new applications, new databases, messaging layers, and more — all while keeping in mind that the core system still had to keep running.
This talk shares the story, the obstacles we faced, and how we dealt with them. And in the end, how this whole operation saved us from a potential disaster.
Mojmir Nebel is the leader of the internal IT development team at ČEZ Prodej, a.s. He is also a long‑time member of the CZ JUG community, an enthusiastic Java developer, and someone who is always eager to explore new technologies.
Talk 2:
🎤 "Warmed up Java, open and closed world AOT" - by Michal Karm, IBM
Ahead-Of-Time (AOT) compilation, build-time initialization to dramatically boost startup times for Java applications.
We take a look at project Leyden that has been delivering AOT features since JDK 24. Open-world, dynamic, traditional Java AOT as gradually implemented by project Leyden.
We also mention GraalVM Community Edition, closed-world AOT and native-image for applications and frameworks specifically friendly to the closed-world assumption.
Karm is a programmer, nouveau cirque acrobat, father, and retro computing tinkerer who Spent years with httpd, Tomcat, load balancing, TLS termination, and doubled with DNS resolvers and malware detection. He firmly believes that 16ms is a very long time and that cache locality is the king. Currently he is neck deep in OpenJDK, Java ahead of time compilation, GraalVM and Quarkus framework at IBM.
When & where?
📍 The meetup will happen on March 10h, 2026, at CEZ office in Prague (Vyskočilova 1461, 140 00 Praha 4)
🕠 Door open at 5:30 PM and we will start with talks at 6:00 PM.
What's our plan for the evening?
The first part will be dedicated to the presentations on Java topics presented by speakers from leading software companies.
🍔🍻 After the talks we're planning a networking session to let the folks meet & chat informally, as well as some delicious food & drinks to keep you fueled throughout the evening!
Special instructions on how to get to the venue:
TBD closer to the date.
CZJUG Prague meetups are supported by:
JetBrains - Pro Developer Tools
OmniFish - GlassFish and Jakarta EE support
Sky - Video streaming
Oracle
This event is supported by:
CEZ Group - Czechia's largest energy group