📢 Rare opportunity: my team is hiring! We're looking for a new Developer Advocate to cover server-side Kotlin, focusing on Spring. If you love Spring, Kotlin, and their communities, this might just be for you. Learn more and apply here:

Jackson 3 lands in Spring Boot 4! The new JsonMapper replaces ObjectMapper with immutable, thread-safe configs. Better date handling, unchecked exceptions for cleaner lambdas, and JSON views for precise serialization control. Watch: youtu.be/4cvP_qroLH4 #SpringBoot #Java

Sometimes, small details matter... While polishing Spring Framework 7, Juergen Hoeller has been able to craft a BridgeMethodResolver optimization that massively reduces the reflection performed on bean methods at startup. It has been backported to 6.2.x too. github.com/spring-proje...

🎯 JEP 500 updated to target JDK 26 Title: Prepare to Make Final Mean Final Type: feature Component: core Release: 26 See openjdk.org/jeps/500

Please give it a try and let us know what you think! This is your last opportunity before GA on Nov 20! spring.io/blog/2025/11...

if you are into #webassembly in the EU, there is an embarrassment of riches, but @wasm.io just announced the CFP for this spring!!!! www.papercall.io/wasmio26

And you can even use BeanRegistrar to introduce your own configuration DSL, see github.com/spring-proje... for an example.

🚀 Spring Boot 4 tip: Jackson 3 brings JsonMapper as the preferred way to read JSON! Notice the new import. No more ObjectMapper from com.fasterxml! JsonMapper is now your go-to for JSON operations in modern Spring apps.

Les inscriptions sont ouvertes pour la soirée Spring Boot 4 & Passkeys en partenariat avec le Spring meetup. Par @snicoll.be et @kehrlann.bsky.social Cher Criteo Le lundi 10 novembre prochain www.parisjug.org/events/2025/...

Looks like X is juicing web visit numbers by opening a browser WebView in the background whether the user visits the link or not. They've re-invented pop-under fraud (allegedly). news.ycombinator.com/item?id=4580...

Notre CFP ouvre dans 1 semaine tout pile 🙌 Pas besoin d’avoir 10 ans d’expérience ou d’être une rockstar du dev pour proposer une conférence 💫 Alors, prêt·e à franchir le pas ? ➡️ RDV sur le lien le 10 novembre à 9h : sessionize.com/mixit-2026/

Introduce support for JavaScript, Python and Wasm execution via Graal languages in Spring framework 🎉 github.com/spring-proje... by @seb.deleuze.fr

Spring Boot 4's new BeanRegistrar interface finally gives us a clean way to register beans programmatically! No more wrestling with BeanFactoryPostProcessor for dynamic registration. Perfect for conditional loading & performance optimization 🚀 Blog: danvega.dev/blog/programmatic-bean-registration

Really great to see plans for adding better integrated support for running @graalvm.org language implementations for JavaScript, Python, and WebAssembly in your Spring applications! github.com/spring-proje...

Spring Boot 4's null-safety is here! 🎯 @NullMarked (JSpecify + NullAway) makes nullness explicit. No more guessing if findUserByEmail() returns null. IDE catches NPEs at compile-time. Your type signatures finally tell the truth.

On behalf of the team and everyone who has contributed, I'm happy to announce that Spring Framework 7.0.0-RC3 has been released and is now available from Maven Central. spring.io/blog/2025/10... #java #spring @spring.io

A new feature dropped on start.spring.io! Because you all love YAML so much, we've added radio buttons to switch the configuration format from properties to YAML. Hope you brought a ruler and don't live in Norway!

Today I presented to the Wasm CG a proposal for fine-grained dynamic code generation as a core WebAssembly feature. The proposal is now at phase 1! github.com/WebAssembly/... Also immortalized in song: suno.com/song/19e0679...

Finally managed to squeeze the follow-up (to "Jackson 3.0 released") blog post out -> cowtowncoder.medium.com/why-upgrade-...

It may not be obvious if you have not tried a #Spring Boot 4 RC yet, but I consider Spring Boot modularization as the most important enhancement that this new generation is introducing. The Spring Boot team has just published a related blog post, this is a must read! spring.io/blog/2025/10...

I have updated the blog post after Spring Boot 4.0.0-RC1 release, which restores in a deprecated form the Jackson 2 auto-configuration to help migrating, and Spring Security 7.0.0-RC1 one that leverages "safe default typing".

Kotlin 2.2.21 and 2.2.20 have a lot goodies in them. In my video, I'm looking at the highlights! www.youtube.com/watch?v=QWpp...

💳 Processing 43B+ transactions a year, Worldline needed a language that could evolve with their growth. Kotlin’s concise syntax, type safety, and Java interoperability help their backend engineers deliver at scale. 🎥 Watch the testimonial from Worldline’s lead developer. youtu.be/3IxDICQTutw?...

I am happy to share that we have released Spring Boot 4.0.O-RC1. This release candidate concludes our modularity efforts, migration to Jackson 3 with support for using Jackson 2 in a deprecated fashion, and more. Please give it a try and let us know what you think! spring.io/blog/2025/10...

The Kotlin/Wasm based Compose for Web browser debugging capability that @sebi.io demoed below is very nice (kotlinlang.org/docs/whatsne...). Showing example here in ClimateTrace KMP/CMP sample (github.com/joreilly/Cli...).

Nice demo from @fniephaus.com from the @graalvm.org team of a Spring Boot application summarizing various files with MarkItDown and Hugging Face Transformers popular Python libraries with GraalPy. github.com/fniephaus/gr...

Le nouveau site web @mixitconf.org est en ligne mixitconf.org. Plusieurs nouveautés comme des couleurs en fonction de votre humeur, un site plus performant et pour ceux qui veulent savoir le budget MiXiT et comment il se répartit une nouvelle page qui vous donne toutes les infos

The Spring team has just released Spring Framework 7.0.0-RC1 with new features like automatic context propagation for Kotlin coroutines, a Jackson 3.0.0 baseline and much more. The final version is planned next month! spring.io/blog/2025/10...

You are wondering if #Spring could run in a #WebAssembly engine like the one in your browser? The GraalVM team did it with Web Image. You don't believe me? Check the related demo graalvm.github.io/graalvm-demo... and the Devoxx talk www.youtube.com/watch?v=uefc... !

The talk Brian Clozel and I gave at #Devoxx is already online. Always great to share the stage with Brian. We covered what’s next for Spring Boot: API versioning, resiliency, OpenTelemetry, structured concurrency, and more. Watch here: www.youtube.com/watch?v=4NQC... #Java #SpringBoot

Recording of my talk at @devoxx.com 2025 with @starbuxman.joshlong.com is now online! Watch for 50 minutes live (pair)coding entertainment showing GraalVM performance 🚀 for Spring apps, how you can mix in Python 🐍, and some more crazy demos 👀. Let me know your comments! m.youtube.com/watch?v=YlMi...

I blogged again: cowtowncoder.medium.com/jackson-3-0-...

And the recording is now here, too: www.youtube.com/watch?v=h16n...

Thank you to everyone who joined our session on boosting Java performance with Project Leyden, Java 25, and Spring Boot! 🚀 @0.5ritter.de and I hope that you will apply the optimizations and tips we shared today. The slides we used: www.slideshare.net/slideshow/su... #JDK25 #SpringBoot #Performance

A long spring, 3 core qualities. @poutsma.bsky.social at #Devoxx

radically cool work going on with wasm wasip3+ getting initial push towards host/green threading, by @tartanllama.xyz. way above my head but obviously freaking awesome. github.com/bytecodealli...

I have just published "Introducing Jackson 3 support in Spring" with hopefully useful insights on Spring Boot 4 upcoming JSON support and on the migration from Jackson 2. spring.io/blog/2025/10...

🍃 ICYMI, #SpringFramework 7.0 and #SpringBoot 4.0 will have a #JUnit Jupiter 6.0 baseline! 🚀 github.com/spring-proje... github.com/spring-proje...

Thu, Oct 9th, 5:40pm – Meet the Spring Team – m.devoxx.com/events/dvbe2... With @starbuxman.joshlong.com, @garnier.wf, @tzolov.bsky.social, @0.5ritter.de, @snicoll.be, @chemicl.bsky.social, Brian Clozel, and yours truly. ☕️🍃 5/5

Jackson 3.0.0 (GA) release now starting! github.com/FasterXML/ja... #java #json #xml #csv #cbor #csv

Ok, thanks to nudging by people I respect a lot (& help by the same), I got into some Last Minute Documentation Work -> github.com/FasterXML/ja... help would be appreciated (like, prs etc) before I go out and push Jackson 3.0.0 GA sometime this week.

#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...

Highly-recommended reading: The state of HTTP clients in Spring by Brian Clozel spring.io/blog/2025/09... « This is also a good time to reflect on the state of HTTP clients in Spring, so we will use this opportunity to explain an important announcement: we are officially deprecating RestTemplate. »

📢 New #WasmAssembly podcast episode: CG, WG, W3C, Lively — #Wasm standardization with Thomas Lively! We talk about Thomas' role as co-chair of the #WebAssembly Community Group at the W3C and the two proposals he champions. 🍿 www.youtube.com/watch?v=MDGq... 🎧 wasmassembly.libsyn.com/cg-wg-w3c-li...

The @springio.net 2026 website is coming along nicely and CFP will open soon. What topics would you love to see at #springio26? 👇

Pointe du Raz, Bretagne

Enjoy my new, artisanal blog post about #JSpecify and #NullAway, a fresh take on null safety in the #Java world. Be warned, may contains #Lombok. Happy weekend you all. info.michael-simons.eu/2025/09/26/j...

Presqu’île de Crozon, Bretagne