Amsterdam Java User Group

Join in with the latest Amsterdam JUG Meetup at Miro, Fred. Roeskestraat 100, 1076 ED Amsterdam.

Notes:

• Parking may be provided, we're exploring this, watch this space.
• Vegetarian food options will be included.
• Tip: this coming Friday, June 27, is SREday in Amsterdam, use JUG50 as the discount code to get a 50% discount: https://sreday.com/2025-amsterdam-q2

For more details and discussions on the below, go to bit.ly/join-foojay-slack to join the Friends of OpenJDK (Foojay.io) Slack and use the #jug-amsterdam channel for conversations related to the below.

In this meetup, in addition to food, drinks, and networking, you will experience four excellent talks of approximately 30 minutes each:

18:00 - Doors Open (And Food!)
19:00 - 19:30 Talk 1: Ko Turk (Codelab)—"Asynchronous Job Processing in Java with JobRunr"
19:30 - 20:00 Talk 2: John Ceccarelli (Azul)—"Java Performance: Beyond Simple Request Latencies"
20:00 Short Break
20:15 - 20:45 Talk 3: Sergey Chernov (Miro)—"Monolith Server Build Optimization"
20:45 - 21:15 Talk 4: Murat Ozkan (Miro)—"Breaking Up the Monolith: A Developer's Guide to Taming the Beast"
21:15 - Networking drinks

Abstracts

"Asynchronous Job Processing in Java with JobRunr"—Ko Turk (Codelab)

JobRunr is a Java library that helps developers offload their (long-running) tasks to the background asynchronously, increasing the application's performance.

In this session, we show you how to use the library with your application with live coding and discuss in depth how you can queue, schedule, or schedule a recurring background Job in JobRunr's JobScheduler class. Also, seeing that you can use a dashboard to monitor your jobs is excellent in the past or in the future.

"Java Performance: Beyond Simple Request Latencies"—John Ceccarelli (Azul)

When someone says "Java performance", most Java devs hear "request latency" and a large part of them say "I'm already meeting my SLAs" or "my app isn't latency-sensitive". But Java performance has many dimensions, each of which play important roles in all kinds of Java apps, from an ultra-low-latency FX trading platform to a long-running data ingestion job running at 2AM on a Saturday.

In this session, we'll go beyond the basics to examine the full landscape of Java performance: median latencies, lantency outliers, freezes, pauses, server max carrying capacity, application behavior at the start of a run, carbon footprint, and more. We will look at tools in new OpenJDK versions and in other JVM distributions to optimize the behavior that most matters to your team.

"Monolith Server Build Optimization"—Sergey Chernov (Miro)

In this session, we'll talk about build optimizations, compare Maven and Gradle build tools.

Then we'll share optimizations of a huge Miro monolith application: faster compilation, test distribution and build caching.

There are few custom solutions that were built, and these solutions are available open-source.

"Breaking Up the Monolith: A Developer's Guide to Taming the Beast"—Murat Ozkan (Miro)

Are you tired of the slow pace and high risks associated with monolithic applications? In this session, we share our journey of transforming a complex, monolithic codebase at Miro. We'll dive into the real-world challenges that motivated our move, from everyday difficulties that developers face to the fear surrounding each deployment. We will explore parts of our journey in tackling code-level complexity to improve our development experience.

We'll also explore the high-level strategies we are currently navigating, including our plans for managing the evolution of the monolith and laying the groundwork for a more modular system.

This talk is for any developer or team lead feeling the pain of a monolith and looking for a strategic path forward.