Sebastian Kuehnau

Off to Switzerland! 🇨🇭 The @jugch tour starts tomorrow. I’m hitting the road to show you how to build modern web UIs in pure #Java. Let’s give your backend the face it deserves with @vaadin. 🦌 03.03. 📍 Bern 04.03. 📍 Lucerne 05.03. 📍 Zurich Details: jug.ch/events.php

@siancu @simas_ch @jugch @vaadin I put Basel on my list for next time ! I hope you can make it Zurich this time 🙏

@seb_vaadin @simas_ch @jugch @vaadin Too bad you’re not coming to Basel as well …

I'll be visiting @jugch next week & talking about: "Your backend deserves a face."! 🇨🇭 No API pain, no JS fatigue – just building modern web UIs in pure Java with @vaadin . Meet me in Bern (3.3.), Lucerne (4.3.), and Zurich (5.3.). Join me here: jug.ch

Exciting news! 🎉 #VaadinCreate 2026 is coming to #Barcelona! Join us for two days of coding, real-world #Java insights & connecting with top engineers. Get your Early Bird ticket before March 31 👇 🔗 bit.ly/4a52pCv

If your #JavaSwing app is costly to update, hard to distribute, or UX-limited, the question isn’t if you modernize — it’s how. Swing Modernization Toolkit lets you run Swing in the browser & modernize incrementally all in #Java. See how it works👇 🔗 bit.ly/49WWdxO

Update: the Spring Boot + Vaadin webinar on Java container images is now happening tomorrow (Jan 20), same time. @cat_edelveis and @MiikkaAnd will cover layering, image size, startup time, and practical hardening. 🕒 18:00 CET / 12 PM ET / 9 AM PT 🔔 pages.vaadin.com/creating-a-per…

🛠️ Get Started: 📖 Documentation: vaadin.com/docs/latest/fl… 💻 Source Code: github.com/SebastianKuehn…

🚀 Upgrade your @vaadin State Management with Signals! I’m demoing Vaadin Signals: A reactive, thread-safe way to manage state across components and browser tabs. 🌐 Links and source code in the replies! 🧵

@CVEnew A fix is already available. Details and update instructions: vaadin.com/security/cve-2… If you're affected: please patch!

CVE-2025-15022 Action captions in Vaadin accept HTML by default but were not sanitized, potentially allowing Cross-site Scripting (XSS) if caption content is derived from user input… cve.org/CVERecord?id=C…

🚀 Release announcement: vaadin-jOOQ-archetype 1.0.0 I just released version 1.0.0 of my Vaadin jOOQ Maven Archetype. It helps you bootstrap a modern Java full-stack application with: - Vaadin 25 - Spring Boot 4 - jOOQ Clean, production-ready defaults The goal is simple: start fast, keep control over SQL, and stay productive without unnecessary complexity. 👉 GitHub: github.com/martinellich/v… Feedback and contributions are very welcome. #java #vaadin #jooq #springboot #fullstack #keepitsimple

@vaadin 25 is out! To celebrate, I built a simple real-time chat app — all in Java, no HTML/JS/CSS. UI built with Vaadin’s built-in components. ▶️ Video below 📦 Source code: github.com/SebastianKuehn… #Vaadin #Java #WebDev #UI

Want to add a filter to a @vaadin Grid – in Java only? Drew shared a nice example showing how simple it can be. 🔗 Code: github.com/drewharvey/vaa… Great for dashboards & CRUD apps. #Vaadin #Java #WebDev

var deadline = LocalTime.of(23,59); if (LocalTime.now().isBefore(deadline)) checkout("-30%"); else System.out.println("See you at full price 😅"); Final hours → 2026.europe.jcon.one/tickets #JCON #JCON2026 #Java #Conference #LastCall #Sale

Nächsten Mittwoch, 3.12. spreche ich über Spec-driven Development bei der Java User Group Switzerland in Bern Kommt vorbei, ich freue mich auf euch! jug.ch/html/events/20…

Web UI with just #Java and @vaadin. Text field → Button → Grid — all in 30 seconds. No HTML. No JS. #Vaadin #WebDev #DX

I had a lot of fun at yesterday's webinar on Spec-driven Development. Therefore, there will be another webinar this time on Spec-driven Testing next Tuesday at 4:00 PM CET. We'll see how to test the Vaadin application from the first webinar, browserless with Karibu Testing and end-to-end with Playwright. Who's in? youtube.com/watch?v=3ReLE_… #AI #SpecDriven #KeepITsimple

Auf dem Weg zur JUG Görlitz, wo ich heute Abend eine Präsentation über @vaadin halte. Die Zeit im Zug wird noch intensiv genutzt. Los geht es um 19 Uhr in den Räumlichkeiten von @QESTIT_GROUP. Ich freue mich auf euer kommen!

@simas_ch What is your approach to correct or improve the results from the MCP server?

MCP has a significant influence on AI agents. It can fundamentally improve the results. However, if the results of the tools are not good, it can also have a negative effect. I run a Karibu Testing MCP server, and it had a bug related to testing confirmation dialogs. It took me a while to understand why Claude Code couldn't create proper confirmation dialog tests. Conclusion: MCP servers require thorough review and testing.

Ich spreche am 13.11. bei der #JUG Görlitz über @vaadin: Fullstack-Web mit Java – direkt, produktiv, ohne JS-Overhead. 📍 QESTIT Görlitz, 19 Uhr 📎 Infos: jug-gr.de/talks/2025-11-… #Java #WebDev #Vaadin

👾Vaadin Tutorial for Beginners: Beautiful UIs in Pure Java My new step-by-step tutorial on using @vaadin with @springboot to build awesome UIs. Create a login page, filtered search, and update form in just 15 minutes. No HTML or JS needed! youtu.be/67oJxPRa3Mg