Amsterdam Java User Group

Tue, Nov 11 · 17:00 CET

Friends of OpenJDK at Uber

Uber, Amsterdam, Burgerweeshuispad 301, Amsterdam, NL

Uber Tech is partnering with Java User Group Amsterdam to host their second mini conference with Friends of OpenJDK. Come and join in at the Uber Amsterdam HQ and learn from experts in their fields.

This meetup will be hosted by Uber Tech, in their office at Uber, Burgerweeshuispad 301, Amsterdam.

Uber requests all our fullnames, email address, and phone number, for security reasons. Some may object to this and in that case, feel free to deregister from the meetup, although we'll very much miss having you. It will be a great event as always and the Uber office is a super cool place, plus they're actively hiring, so please come for that reason too. The place to send these details to is amsterdamjug@googlegroups.com, i.e., drop a quick mail there with your fullname (first and lastname), email address, and phone number, we'll pass this on to Uber, who will not make use of these details in any way, i.e., you won't get spammed.
Thanks and apologies for the inconvenience.

Note:

• This event is targeted to be suitable to more experienced / senior Java engineers. Especially if you're a more senior engineer, you're very warmly invited to attend.
• Also note that Uber is actively searching for a Sr Staff Engineer, JVM in Amsterdam, ideally with 10+ years of engineering experience, plus will assist with relocation and visa related requirements, if needed. Job description here: https://www.uber.com/global/en/careers/list/146831/

Agenda

17:00 - Doors Open and Food

17:45 - Intro to Uber Tech Amsterdam, JUG Amsterdam, and Foojay.io

18:00 - "Large-Scale Upgrades: Lessons Learnt", Pavel Belousov, Staff Software Engineer, JVM Platfrom, Developer Platform, Uber

18:30 - Break

18:45 - "Are We Ready For The Next Cyber Security Crisis Like Log4Shell?", Soroosh Khodami, Solution Architect, Code Nomads

19:15 - Break

19:30 - "Scotty I Need Warp Speed: Ways to Improve the JVM Startup/Warmup", Gerrit Grunwald, Azul

20:00 - Doors Close

Abstracts

"Large-Scale Upgrades: Lessons Learnt", Pavel Belousov, Staff Software Engineer, JVM Platfrom, Developer Platform, Uber

This presentation details the challenges and strategies involved in major dependency migrations, specifically focusing on shifts like Java version bumps, Spring Boot 2 to 3, and the transition from JUnit 4 to 5.

We will emphasize the critical lessons that technical debt accrues exponentially: the longer the delay, the higher the cost and complexity of the upgrade.

Finally, we'll compare the upgrade paths, team coordination, and tooling implications when performing these migrations within both monorepo and polyrepo architectural paradigms.

"Are We Ready For The Next Cyber Security Crisis Like Log4Shell?", Soroosh Khodami, Solution Architect, Code Nomads

We'll explore critical cybersecurity challenges in today's software ecosystem, where vulnerabilities like Log4J, Spring4Shell, and the XZ Backdoor have created significant risks.

Learn from Soroosh Khodami, a hands-on solution architect with experience in security platform services for enterprises like Rabobank, as he shares practical strategies for securing software development processes applicable to organizations of all sizes.

Discover how basic SQL Injection threats can extend beyond database access, understand the dangers of supply chain attacks, and identify effective practices to secure CI/CD processes.

Explore the concepts of Shift-Left Security and DevSecOps, learn how Software Bill of Materials (SBOM) can help prepare for future security crises, and understand the implications of EU supply chain security regulations like DORA/CRA for developers.

"Scotty I Need Warp Speed: Ways to Improve the JVM Startup/Warmup", Gerrit Grunwald, Azul

When running Java in the Cloud, the JVM startup time can become a limitation. Especially when you look at spinning up new instances of an app as response to changes in load, the warmup time can be a problem.

A couple of years ago, you only had CDS that could help you with the startup, but meanwhile there are a couple of solutions that can help you to let you JVM start super fast.

These days we have AppCDS, CRaC, Native Image, Leyden, InstantOn, Ready Now, JITServer and Cloud Native Compiler, which are all solutions that help to reduce the startup time of a JVM. Each of those is not a Silver Bullet, so you have to choose the right solution for your problem.

This session will give you a short overview of the different solutions to increase your JVM startup performance and will try to give you some hints on how to choose the right solution for your application.

Thu, Nov 27 · 17:30 CET

Amsterdam JUG Meetup at Pegasystems

Pegasystems, Strawinskylaan 3011, Amsterdam, NL

Join in with the latest Amsterdam JUG Meetup at Pegasystems, Strawinskylaan 3011, 1077 ZX Amsterdam.

Note: There is no free parking.

17:30 - Doors Open (And Food!)
18:00 - 18:45 Talk 1: Guus de Wit (Adesso)—"Snake in 10 Lines: Learning More by Coding Less"
18:45 Short Break
19:00 - 19:45 Talk 2: Vasilii Kudriavtsev (Pegasystems)—"Memory Optimization Techniques in Java"
19:45 Short Break
20:00 - 20:45 Talk 3: Nupur Sharma (Qodo)—"AI Context-Awareness: A Key to High-Quality Code"
21:00 - Doors Close

Abstracts

Talk 1: Guus de Wit (Adesso)—"Snake in 10 Lines: Learning More by Coding Less"

Can you create a complete game with just 10 lines of code? That was the quest I set myself when recreating the classic game Snake in as few lines as possible.

Let me tell you: I was not ready for the types of challenges I would face. For example, just registering button presses was not as straightforward as I had hoped. Through live coding, I will show you how I overcame these obstacles and distilled Snake to its absolute essence. What key elements make this game instantly recognizable?

By combining Kotlin and Swing, we will end up with a minimal code base and if not award-winning, at least a playable version of Snake. Striving for conciseness led me to a deeper understanding of the code.

I will show how constraints push us to think outside the box and lead to more creative solutions. Moreover, my approach can be applied to any problem. Sometimes the best way to understand code is by seeing how little of it you actually need!

Talk 2: Vasilii Kudriavtsev (Pegasystems)—"Memory Optimization Techniques in Java"

Let's explore practical memory optimization techniques in Java that deliver significant impact through small, targeted code changes. Rather than focusing on JVM tuning parameters, garbage collector settings, or algorithmic redesign, the presentation concentrates on code-level techniques that reduce memory consumption by creating fewer objects.

The session emphasizes approaches with minimal cognitive load that can be applied during regular development, targeting long-lived data structures where object proliferation becomes problematic—typically when dealing with tens of thousands of business objects that amplify into millions of Java objects in memory.

Talk 3: Nupur Sharma (Qodo)—"AI Context-Awareness: A Key to High-Quality Code"

Discover how to implement and tailor powerful automations within your review process.

We'll show how these workflows accelerate and enhance the development cycle through methods like:

• Flagging Contextual Issues: Automatically reviewing changes based on deep system context rather than generic rules.
• Facilitating Accelerated Reviews: Providing developers and reviewers with immediate, high-fidelity feedback, drastically cutting down manual review time.
• Enforcing Best Practices: Consistently applying your organization’s specific coding standards and architectural patterns across all projects.