blog.jetbrains.com/kotlin/2025/... real life code examples that showcase how Kotlin can improve the quality of your codebase, by leveraging features built in the language

Short blog, but I think it really hits the spot on the skills great software engineers have 👍 terriblesoftware.org/2025/11/25/w...

JUnit is undoubtedly one of the most important projects in the #Java ecosystem. And it's 100% free and open! Let me be frank: If we can't get THIS project to the point where a single maintainer can focus on it, then what does that say about our commitment to Free & Open Source Software? 1/3 ⏩

blog.jetbrains.com/kotlin/2025/... great blog post that proves why moving to Kotlin is a good choice. @jlengrand.bsky.social and I can vouch for that 😉

Exciting News 🎉 Spring Boot 4.0.0 is here: spring.io/blog/2025/11...

When I introduce mutation testing to teams on the Code Craft training workshop, it's invariably one of those "How did this not occur to us before?" moments. "Is our code broken and we don't know it?" Let's break it and see if any of your tests fail.

I'm documenting Spring Boot 4 features with: ✅ Code examples ✅ Video tutorials ✅ Blog deep-dives All organized in one central repo 👇 github.com/danvega/sb4

At this year's @devoxx.com I had a chat with @smarks.bsky.social on ensuring immutable collections when creating a Java record. His suggestion was interesting enough to warrant a new blog post on the subject: codeadventures.littlebluefrog.nl/posts/09-col...

Spring Framework 7.0 is now GA! Including Java 25 (with Java 17 baseline), Jakarta EE 11, JSpecify null-safety, Jackson 3.0, Kotlin 2.2, JUnit 6.0, plus programmatic bean registration, JmsClient, API versioning, HTTP Interface Client, RestTestClient & more: spring.io/blog/2025/11...

I have a technique I call incompetence-based-mutation-testing. Start making some changes. Bork everything, comment out half the existing code to just make stuff compile. Run tests. Watch tests pass. Stop refactoring, go have a stern word with the tests.

The reason for creating tests is not to achieve 80% code coverage, but to gain the assurance that the application will still work after a change.

Nice to see @balarawool.bsky.social 's talk at #Devoxx on the featured talks list 🤩 It's a great overview, often with some hidden gems, as long as you don't focus too much on the viewer numbers. Some subjects and conferences receive more traffic.

techtrenches.substack.com/p/the-great-... An eye-opener read for whoever is working with tech and sees the AI hype rise above control.

"...and at the end, all the tests were passing." I've seen them do it. Lots of other devs have seen them do it. LLMs will sometimes cheat to make test suites green. They'll change assertions, comment out failing tests, set them to be ignored, or just plain delete them. Two words: mutation testing

Looking forward to participating in this meetup! In great company too 😄

#OpenRewrite v8.63.0 is out! 🍂 🚀 Spring Boot to Quarkus migration recipes 🛠️ Oracle/MSSQL to PostgreSQL migrations 🤠 Jackson v3 upgrade recipes 🍁 Support additional Maven (re)sources 🧪 JUnit 5, 6 & Jupiter best practices 🔧 Expanded Hibernate 7 migration ➕ Many more fixes github.com/openrewrite/...

Closing @devoxx.com with the final talk by @balarawool.bsky.social about virtual threads and the new concurrency features of the JDK

The final reckoning is coming 😄 #devoxx

Finally...

Ending of #devoxx

JUnit 6 is here! Ready to upgrade? We’ve got you covered with step-by-step recipes to move from 3 → 4 → 5 → 6. docs.openrewrite.org/recipes/java...

#JUnit 6.0.0 is released! ✨ Java 17 and Kotlin 2.2 baseline 🌄 JSpecify nullability annotations 🛫 Integrated JFR support 🚟 Kotlin suspend function support 🛑 Support for cancelling test execution ⏭️ New `--fail-fast` mode for ConsoleLauncher 🧹 Removal of deprecated APIs docs.junit.org/6.0.0/releas...

All Devoxx Belgium 2025 eTickets have been emailed🎟️ ✔️ Check your inbox (or spam) ✔️ Download to your phone/tablet ✔️ Show QR code at entrance for your badge ✔️ Max screen brightness = smooth scanning ✨

My very first contribution on the ING Tech Blog! I’m excited to share my experience with mutation testing and how it’s vital to strengthen your test suite to gain code quality and resilience. Test smart. Test strong. Trust your code. medium.com/ing-blog/gai...

Just finished marking all my favorite talks happening at @devoxx.com , so many interesting ones! Looking forward to it

www.atlassian.com/continuous-d... “Good coverage does not equal good tests” Don’t reach for a number, reach for a strong test suite. Inspire a culture in your team rather than putting a target to reach. It will take you more time and effort, but the payback value is far higher.

reg.devoxx.be/event/dvbe25 🔥🚀👀

Hope to see you there!! I’ll be showcasing how introducing mutations in code will highlight gaps in the test suite. Theory and live demo will be covered!

Fellow software developers using Maven, what is your opinion on using Bill of Materials to manage your dependencies versioning?

@devoxx.com is amazing tech conference and I am super happy to be part of it as a speaker again 🤩

Immutability is a great feature that everybody should start using in their code. Thank you @johanhutting.bsky.social for advocating it!

Just as it is a good practice to make all fields private unless they need greater visibility, it is a good practice to make all fields final unless they need to be mutable. - Brian Goetz #quotes #quoteoftheday

Quality of tests is a reflection of the quality of code under test.

Be the change you want to see in the world. Sometimes approaching a young speaker at the end of their presentation and thanking them for the session is enough to make their day. Words of encouragement go a long way. Be kind and excellent to each another.

Our talk at #JNation in Coimbra with @vasco-veloso.bsky.social about going green with native is already available online! 🤩 We cover the why, how native might benefit your resource usage and how to measure it with free tools using @graalvm.org native builds: www.youtube.com/watch?v=KmXs...

Vasco Veloso and Johan Hutting are live at JNation 2025 with: “Going green with native: efficient, sustainable software”. A session on performance, native builds and reducing software’s resource impact. #JNation #Java #Coimbra #CloudNative #SustainableSoftware

Strengthening Kotlin for backend development: @jetbrains.com partners with the Spring team! 🎉 🤝 This strategic partnership is a part of our continued efforts to make Kotlin a top choice for professional server-side work. Read the full news: blog.jetbrains.com/kotlin/2025/...

It was an honor and such a fun day shooting this video!

Really like the prerequisite of having a strong and effective test suite before even starting migrating your code. This is the only way to make sure that no technical debt is introduced or kept during the process.