Frederik Pietzko
Fullstack Kotlin Enthusiast
Aachen, Germany
Actions
Frederik started programming in 8th grade, starting out programming Lego Mindstorms and later learning Java and Python for personal Projects.
16 years later, Frederik is a Developer with 8 years of professional experience who regularly presents at international conferences and writes the occasional blog post.
In his free time, he likes to explore programming languages and frameworks, meet and chat with other software enthusiasts, and play with his cats.
Links
Area of Expertise
Topics
Performance Optimized Spring Boot for the Cloud
In the era of cloud-native applications, optimizing performance, scalability, and observability is crucial for delivering robust and efficient services. This session will explore best practices for optimizing Spring Boot applications specifically for cloud environments. We will delve into key strategies for enhancing performance, including efficient resource management and asynchronous processing.
Additionally, we will discuss how to implement observability in Spring Boot applications using tools like Spring Actuator, Micrometer, and distributed tracing. Attendees will learn how to monitor application health, track performance metrics, and gain insights into system behavior, enabling proactive troubleshooting and optimization.
By the end of this session, participants will have a comprehensive understanding of how to build and maintain high-performance Spring Boot applications in the cloud, ensuring they can scale effectively while maintaining optimal performance and observability.
Things you can do with Spring Boot and Kotlin
In this talk, I’ll show you how to build microservices efficiently using Kotlin and Spring Boot.
We’ll begin by exploring Kotlin as a drop-in replacement for Java and gradually dive into Kotlin-specific features and libraries that significantly enhance development. We’ll also take a closer look at Kotlin DSLs for Spring Beans, Routing and Security as a sleek alternative to annotation-based configurations essentially turning Spring Boot into a microframework.
Come and join me on this live coding adventure!
How to kill JavaScript from your Stack with HTMX and Kotlin
Tired of juggling TypeScript, React, REST APIs, and countless dependencies just to build a web app? What if I told you there's a simpler way that doesn't sacrifice interactivity or type safety?
In this talk, I'll show you how to build full-stack web applications using nothing but Kotlin DSLs and HTMX. No templating engines that break when your data changes. No frontend frameworks to learn. No JSON serialization headaches. Just clean, type-safe Kotlin code that generates dynamic HTML and delivers SPA-like user experiences.
You'll see live examples of routing, real-time validation, smooth page transitions, and reusable components - all without writing a single line of JavaScript. By the end, you'll have a completely new perspective on web development that's both simpler and more powerful than the traditional approach.
Perfect for developers who want to build modern web apps without the modern complexity.
The Road Not Taken: A Developer's Guide to Life Beyond Spring Boot
Beyond Spring Boot lies a world of possibilities waiting to be explored. Join me as we chart a course from heavyweight champions Quarkus and Micronaut, through the versatile terrain of Helidon, to the surprisingly capable micro-frameworks Javalin and Ktor. We'll compare approaches, analyze performance, and uncover the unique strengths each brings to your development arsenal. The journey from enterprise to lightweight might just change how you choose your next framework.
SpinKube in Action: Fast‑Starting, Scale‑to‑Zero Wasm Workloads on Kubernetes
WebAssembly is moving from the browser to the cluster, offering sub‑second cold starts, strong isolation, and a tiny footprint. In this session, we’ll demystify Wasm and WASI, show how Kubernetes runs Wasm via runwasi and containerd shims, and put it all together with Spin and SpinKube.
We’ll walk through SpinKube’s CRDs and operators, then live‑demo deploying simple microservices and serverless wasm function, scaling them down to zero and back up under load. You’ll leave with a clear mental model for when to choose Wasm, how to run it in Kubernetes, and a repeatable path to ship and operate Spin apps with SpinKube.
Ditch Python and build Enterprise-Ready AI Agents on the JVM with Koog
Python dominates AI agent development—but it's a nightmare in enterprise. Integrating Python agents with your Java/Kotlin infrastructure means building brittle bridges, managing separate deployments, and praying your agents don't hallucinate away your business logic.
Koog changes the game. Built natively for Kotlin and the JVM, it lets you build sophisticated multimodal agents that integrate directly with your existing systems. No MCPs. No Python interop headaches. No custom workarounds.
But what really sets Koog apart? Enterprise features that actually matter: automatic checkpointing and state restoration on every graph node, so that long-running agents can pause and resume without losing context. Tool call side effects and rollbacks that let you recover gracefully from agent mistakes without expensive re-runs. Built-in observability with LangFuse so you can actually see what your agents are doing.
We'll build a real, production-grade AI agent live on stage—from zero to enterprise-ready—showing you how these features eliminate months of custom engineering. By the end, you'll see why the JVM is where intelligent agents belong.
Building Production-Ready Kubernetes Operators: A Practical Guide
Kubernetes operators have revolutionized how we manage complex, stateful applications on Kubernetes. By encoding domain expertise into custom controllers, operators extend Kubernetes capabilities and automate operational tasks that would otherwise require manual intervention.
In this session, we'll explore the fundamentals of building a Kubernetes operator from scratch. You'll learn how to:
- Understand operator patterns: Discover why operators are essential for managing sophisticated applications and how they leverage Kubernetes' declarative model
- Design custom resources: Learn how to define Custom Resource Definitions (CRDs) that model your application's desired state
Implement robust controllers: Build controllers that reconcile the current state with the desired state, handling edge cases and failures gracefully
- Test and deploy: Explore best practices for testing operators and deploying them safely into production environments
The Anatomy of Kotlin DSLs
Kotlin has revolutionized development on the JVM with its expressive syntax and powerful features. Among its most celebrated capabilities is the ability to create Type-Safe Domain-Specific Languages (DSLs). But what actually makes them tick, and how can we use them to write cleaner, more maintainable code?
In this session, we will dissect the anatomy of Kotlin DSLs. Moving beyond simple examples, we will explore practical, real-world use cases. We will demonstrate how DSLs can serve as a superior alternative to the verbose Builder pattern, how they can simplify Spring Bean registration without annotation fatigue, and how they can turn complex test data setup into readable specifications.
We will look under the hood to understand the core language features that make this magic possible -specifically lambdas with receivers, extension functions, and high-order functions.
Finally, we will put theory into practice with a live coding session, building a custom Kotlin DSL from scratch right on stage. You will leave this talk with a deep understanding of the mechanics behind Kotlin DSLs and the confidence to craft your own.
Java is Coming for Python’s Lunch: The Rise of JVM AI Agents
Unfortunately, for the past couple of years, Java developers have felt like second-class citizens in the AI space.
While Python has dominated the headlines, we’ve been left wondering if we’ll need to rewrite our entire stack to create even a mediocre autonomous agent.
However, there is good news: the ‘experimental phase' is coming to an end and soon we will enter into ‘production phase’.
This is when the JVM typically takes over and eats everyone’s lunch.
In this session, we’ll be skipping over the fluff and diving into how Java is finally making its move.
We are going to take a top-level look at three libraries that are changing the rules of the game — each offering a different ‘vibe’:
- Spring AI: for when you want enterprise-grade sleep-at-night stability while leveraging the Spring ecosystem you already know.
- Koog (JetBrains): a Kotlin-native powerhouse that helps agent logic feel clean, reactive, and — dare I say it — fun to write.
- Embabel: a clever newcomer that is helping to simplify prompt engineering by focusing on ‘intent’ rather than simply producing a bunch of messy prompts.
We will give a brief "vibe check" to demonstrate how each handles some of the more complex aspects of memory and calling tools without getting lost in 500-page slides.
If you are tired of "python envy" and want to start creating actual AI agents using a stack that doesn't fail under load, this presentation is for you!
Thinking in Tables: Replacing Hibernate Magic with Exposed Logic in Spring Boot
The database you use does not consist of objects, so why do developers continue to act as though it does? For many, Hibernate's abstraction layer has created more conflict than it solved due to the "magical" behaviour that even an AI cannot debug.
Exposed is a Kotlin SQL framework that appeals to those who enjoy SQL but also appreciate type safety. This presentation will demonstrate how to replace the "magic" of JPA's heavy use of annotations with a more pragmatic and Kotlin-first methodology. The presentation will provide live code examples of how to create Spring Boot applications with an explicit, readable and fast persistence layer. Attendees will learn how to take advantage of Kotlin's language features to build their data layer in a way that is understandable to them, their compiler, and their database.
Java User Group Karlsruhe User group Sessionize Event Upcoming
JAX Upcoming
Things you can do with Spring Boot and Kotlin
DevOpsCon & MLCon 2026 Sessionize Event
JCON EUROPE 2026 Sessionize Event
Devland 2026
Exploring WASM on Kubernetes
SpinKube in Action: Fast-Starting, Scale-to-Zero Wasm Workloads on Kubernetes
Javaland 2026
The Road Not Taken: A Developer's Guide to Life Beyond Spring Boot
Container Days London Sessionize Event
OOP 2026
Exloring WASM on Kubernetes - Night School
https://www.oop-konferenz.de/de/programm/konferenzprogramm/ndi-2
IT Tage Frankfurt
Cloud Native in der Praxis: Optimierung von Spring-Boot-Anwendungen
Kotlin Dev Day 2025 Sessionize Event
W-Jax Munich
How to kill JavaScript from your Stack with HTMX and Kotlin
Devoxx Belgium 2025
Beyond Spring Boot
Cloud Native Summit 2025 Sessionize Event
Java Forum Stuttgart
Wie man JavaScript aus seinem Stack entfernt mit HTMX und Kotlin (Engl. How to kill JavaScript from your stack - with HTMX and Kotlin)
WeAreDevelopers World Congress 2025 Sessionize Event
techcamp 2025 Sessionize Event
Javaland 2025
Wie man Javascript aus seinem Stack entfernt mit HTMX und Kotlin
Please note that Sessionize is not responsible for the accuracy or validity of the data provided by speakers. If you suspect this profile to be fake or spam, please let us know.
Jump to top