Loïc Mathieu
@loicmathieu.fr
Lead Developer @kestra.io, Java & JVM passionate, performance, OSS contributor (mainly Quarkus), Book Author (Quarkus edition ENI), GCP Google Dev Expert.
Like to learn stuff and share what I learned.
https://www.loicmathieu.fr
Like to learn stuff and share what I learned.
https://www.loicmathieu.fr
Pinned
Java 26: what’s new? | Loic's Blog
Now that Java 26 is features complete (Rampdown Phase Two at the day of writing), it’s time to walk through all the functionalities that bring to us, developers, this new version. This article is…
www.loicmathieu.fr
What's new in Java 26 for us, developers?
(Both in English and French)
#java #java26
www.loicmathieu.fr/wordpress/in...
(Both in English and French)
#java #java26
www.loicmathieu.fr/wordpress/in...
Today I discover that the Eclipse Temurin Java images reports the wrong number of available processors on cpu-constrained containers in 21 but not in 25!
You can try by yourself (x86 only)
This is very surpising for such a highly used image.
github.com/adoptium/ado...
You can try by yourself (x86 only)
This is very surpising for such a highly used image.
github.com/adoptium/ado...
Temurin 21 reports invalid number of available processors with respect to 25 in a resource constrained container · Issue #1404 · adoptium/adoptium-support
Please provide a brief summary of the bug In 21, calling Runtime.getRuntime().availableProcessors() reports the total number of CPUs of the host in a container with 1 CPU allocated, whereas in 25 i...
github.com
January 22, 2026 at 1:06 PM
Today I discover that the Eclipse Temurin Java images reports the wrong number of available processors on cpu-constrained containers in 21 but not in 25!
You can try by yourself (x86 only)
This is very surpising for such a highly used image.
github.com/adoptium/ado...
You can try by yourself (x86 only)
This is very surpising for such a highly used image.
github.com/adoptium/ado...
What's new in Java 26 for us, developers?
(Both in English and French)
#java #java26
www.loicmathieu.fr/wordpress/in...
(Both in English and French)
#java #java26
www.loicmathieu.fr/wordpress/in...
Java 26: what’s new? | Loic's Blog
Now that Java 26 is features complete (Rampdown Phase Two at the day of writing), it’s time to walk through all the functionalities that bring to us, developers, this new version. This article is…
www.loicmathieu.fr
January 22, 2026 at 10:45 AM
What's new in Java 26 for us, developers?
(Both in English and French)
#java #java26
www.loicmathieu.fr/wordpress/in...
(Both in English and French)
#java #java26
www.loicmathieu.fr/wordpress/in...
Reposted by Loïc Mathieu
Updated JOL and heapdump-estimates in it specifically to better support JDK 25. We use this tool to quickly glance where are the opportunities in our real services. Streaming heap dump analysis allows doing this on multi-hundred GB heap dumps. Builds: builds.shipilev.net/jol/
January 21, 2026 at 6:27 PM
Updated JOL and heapdump-estimates in it specifically to better support JDK 25. We use this tool to quickly glance where are the opportunities in our real services. Streaming heap dump analysis allows doing this on multi-hundred GB heap dumps. Builds: builds.shipilev.net/jol/
Reposted by Loïc Mathieu
The hardest part of operating data & infrastructure isn’t running workflows, it’s knowing what they touch, what they produce, and what breaks when something changes.
That’s why we built Kestra Assets: a governed, language-agnostic catalog with automatic lineage.
kestra.io/blogs/hello-...
That’s why we built Kestra Assets: a governed, language-agnostic catalog with automatic lineage.
kestra.io/blogs/hello-...
Hello, Assets: Unifies Orchestration, Catalogs, and Lineage
Kestra Assets bring data and infrastructure governance into your workflows. Track tables, files, and cloud resources as first-class assets with built-in lineage, audit logs, dependency graphs, and tea...
kestra.io
January 21, 2026 at 4:32 PM
The hardest part of operating data & infrastructure isn’t running workflows, it’s knowing what they touch, what they produce, and what breaks when something changes.
That’s why we built Kestra Assets: a governed, language-agnostic catalog with automatic lineage.
kestra.io/blogs/hello-...
That’s why we built Kestra Assets: a governed, language-agnostic catalog with automatic lineage.
kestra.io/blogs/hello-...
Reposted by Loïc Mathieu
Tips and tricks for your @kestra.io flows! dev.to/missamarakay...
Tips and tricks for your Kestra flows
Build your best Kestra workflow by following practical tips.
dev.to
January 21, 2026 at 2:32 PM
Tips and tricks for your @kestra.io flows! dev.to/missamarakay...
Reposted by Loïc Mathieu
🎯 JEP 527 updated to target JDK 27
Title: Post-Quantum Hybrid Key Exchange for TLS 1.3
Type: feature
Component: security / javax.net.ssl
Release: 27
See openjdk.org/jeps/527
Title: Post-Quantum Hybrid Key Exchange for TLS 1.3
Type: feature
Component: security / javax.net.ssl
Release: 27
See openjdk.org/jeps/527
January 20, 2026 at 2:25 PM
🎯 JEP 527 updated to target JDK 27
Title: Post-Quantum Hybrid Key Exchange for TLS 1.3
Type: feature
Component: security / javax.net.ssl
Release: 27
See openjdk.org/jeps/527
Title: Post-Quantum Hybrid Key Exchange for TLS 1.3
Type: feature
Component: security / javax.net.ssl
Release: 27
See openjdk.org/jeps/527
TIL that even if a Kafka producer is supposed to be thread safe, it is not in the context of a transaction, so you must wrap your transactional calls into a synchronized block 🤨
January 20, 2026 at 8:40 AM
TIL that even if a Kafka producer is supposed to be thread safe, it is not in the context of a transaction, so you must wrap your transactional calls into a synchronized block 🤨
Reposted by Loïc Mathieu
Après des vacances bien méritées, la Veille de Wittouck 🤓 est de retour avec la même formule pour 2026 : mon analyse rapide des articles, vidéos ou podcasts qui m’ont intéressés sur les deux dernières semaines.
L'édition de début janvier est dispo : codeka.io/2026/01/16/l...
L'édition de début janvier est dispo : codeka.io/2026/01/16/l...
La veille de Wittouck - Début janvier 2026 - Julien Wittouck
freelance solution & software architect 🏗 - containers 🐋 & linux 🐧 ❤️ - teacher & trainer 🎓 @ univ-lille.fr - speaker 🎙 - Team @Cloud_Nord
codeka.io
January 19, 2026 at 8:38 AM
Après des vacances bien méritées, la Veille de Wittouck 🤓 est de retour avec la même formule pour 2026 : mon analyse rapide des articles, vidéos ou podcasts qui m’ont intéressés sur les deux dernières semaines.
L'édition de début janvier est dispo : codeka.io/2026/01/16/l...
L'édition de début janvier est dispo : codeka.io/2026/01/16/l...
Reposted by Loïc Mathieu
“Sleep is not a synchronization primitive.” 😅
We’re featured on @foojay.io 🎉 sharing how we deal with flaky tests at Kestra:
6,000+ tests
async workflows
distributed queues
CI you can actually trust
You won’t kill all flakes.
Separate signal from noise. Ship anyway.
foojay.io/today/flaky-...
We’re featured on @foojay.io 🎉 sharing how we deal with flaky tests at Kestra:
6,000+ tests
async workflows
distributed queues
CI you can actually trust
You won’t kill all flakes.
Separate signal from noise. Ship anyway.
foojay.io/today/flaky-...
foojay – a place for friends of OpenJDK
foojay is the place for all OpenJDK Update Release Information. Learn More.
foojay.io
January 15, 2026 at 4:18 PM
“Sleep is not a synchronization primitive.” 😅
We’re featured on @foojay.io 🎉 sharing how we deal with flaky tests at Kestra:
6,000+ tests
async workflows
distributed queues
CI you can actually trust
You won’t kill all flakes.
Separate signal from noise. Ship anyway.
foojay.io/today/flaky-...
We’re featured on @foojay.io 🎉 sharing how we deal with flaky tests at Kestra:
6,000+ tests
async workflows
distributed queues
CI you can actually trust
You won’t kill all flakes.
Separate signal from noise. Ship anyway.
foojay.io/today/flaky-...
Reposted by Loïc Mathieu
Looking to understand pointer arithmetic in modern Java? How to perform pointer arithmetic using the Foreign Function & Memory API? Check out this insightful piece by @davidvlijmincx.com on our blog. #Java #Programming foojay.io/today/pointe...
Pointer Arithmetic in Modern Java
How to perform pointer arithmetic using the Foreign Function & Memory API to achieve zero-GC memory access.
foojay.io
January 15, 2026 at 12:05 PM
Looking to understand pointer arithmetic in modern Java? How to perform pointer arithmetic using the Foreign Function & Memory API? Check out this insightful piece by @davidvlijmincx.com on our blog. #Java #Programming foojay.io/today/pointe...
Reposted by Loïc Mathieu
Tremplin DevLille x Cloud Nord x Agi’Lille
Tu veux devenir speaker mais tu n’oses pas encore ?
Idée de talk, prise de parole, structuration… on t’accompagne
CFP ouvert le 26 janvier 2026 (clôture : 13 février)
6 coaché·e·s → 3 talks sur scène
Lance-toi, la communauté est là pour toi.
Tu veux devenir speaker mais tu n’oses pas encore ?
Idée de talk, prise de parole, structuration… on t’accompagne
CFP ouvert le 26 janvier 2026 (clôture : 13 février)
6 coaché·e·s → 3 talks sur scène
Lance-toi, la communauté est là pour toi.
January 15, 2026 at 12:10 PM
Tremplin DevLille x Cloud Nord x Agi’Lille
Tu veux devenir speaker mais tu n’oses pas encore ?
Idée de talk, prise de parole, structuration… on t’accompagne
CFP ouvert le 26 janvier 2026 (clôture : 13 février)
6 coaché·e·s → 3 talks sur scène
Lance-toi, la communauté est là pour toi.
Tu veux devenir speaker mais tu n’oses pas encore ?
Idée de talk, prise de parole, structuration… on t’accompagne
CFP ouvert le 26 janvier 2026 (clôture : 13 février)
6 coaché·e·s → 3 talks sur scène
Lance-toi, la communauté est là pour toi.
Reposted by Loïc Mathieu
How stagnant is CPU technology? https://lemire.me/blog/2026/01/14/how-stagnant-is-cpu-technology/
January 14, 2026 at 2:52 PM
How stagnant is CPU technology? https://lemire.me/blog/2026/01/14/how-stagnant-is-cpu-technology/
Reposted by Loïc Mathieu
Quarkus 3.31, released this month, will be the culmination of months of work making Quarkus applications builds faster. Learn more about it in this blog post by @gsmet.bsky.social: quarkus.io/blog/buildin...
Towards faster builds
Quarkus: Supersonic Subatomic Java
quarkus.io
January 14, 2026 at 12:50 PM
Quarkus 3.31, released this month, will be the culmination of months of work making Quarkus applications builds faster. Learn more about it in this blog post by @gsmet.bsky.social: quarkus.io/blog/buildin...
Reposted by Loïc Mathieu
Leave it to me to make more-complex-than-necessary first examples! But the adventure continues and I'm learning a ton. Join me and let me know what you are building with @kestra.io!
dev.to/missamarakay...
dev.to/missamarakay...
More adventures in building a first flow with Kestra.io
We left off on our adventure a bit stuck in the mud with the Google Calendar API.
dev.to
January 14, 2026 at 2:30 PM
Leave it to me to make more-complex-than-necessary first examples! But the adventure continues and I'm learning a ton. Join me and let me know what you are building with @kestra.io!
dev.to/missamarakay...
dev.to/missamarakay...
One more time, the excellent async profiler tools saved me during a customer production incident.
Download iy -> quick flamegraph profile -> immediate discovery of the issue.
github.com/async-profil...
Download iy -> quick flamegraph profile -> immediate discovery of the issue.
github.com/async-profil...
async-profiler
async-profiler has 3 repositories available. Follow their code on GitHub.
github.com
January 14, 2026 at 2:40 PM
One more time, the excellent async profiler tools saved me during a customer production incident.
Download iy -> quick flamegraph profile -> immediate discovery of the issue.
github.com/async-profil...
Download iy -> quick flamegraph profile -> immediate discovery of the issue.
github.com/async-profil...
Reposted by Loïc Mathieu
I did some OpenJDK commit exploration and I thought I could blog about it too. Here it is: questdb.com/blog/jvm-cur...
How a 40-Line Fix Eliminated a 400x Performance Gap | QuestDB
A deep dive into an OpenJDK commit that replaced slow /proc file parsing with a single syscall, revealing obscure Linux kernel internals and a 20-year-old optimization opportunity.
questdb.com
January 13, 2026 at 11:43 PM
I did some OpenJDK commit exploration and I thought I could blog about it too. Here it is: questdb.com/blog/jvm-cur...
Reposted by Loïc Mathieu
ICYMI: You're probably ignoring the best parts of Quarkus.
I compiled 10 "Hidden Gems" that I use in almost every project:
- @Location for easy HTTP headers
- Zero-config Flyway
- The unspoken power of Qute type-safety
Stop writing boilerplate. buff.ly/aPmLiHC
#Java #Quarkus #DeveloperExperience
I compiled 10 "Hidden Gems" that I use in almost every project:
- @Location for easy HTTP headers
- Zero-config Flyway
- The unspoken power of Qute type-safety
Stop writing boilerplate. buff.ly/aPmLiHC
#Java #Quarkus #DeveloperExperience
January 14, 2026 at 8:00 AM
ICYMI: You're probably ignoring the best parts of Quarkus.
I compiled 10 "Hidden Gems" that I use in almost every project:
- @Location for easy HTTP headers
- Zero-config Flyway
- The unspoken power of Qute type-safety
Stop writing boilerplate. buff.ly/aPmLiHC
#Java #Quarkus #DeveloperExperience
I compiled 10 "Hidden Gems" that I use in almost every project:
- @Location for easy HTTP headers
- Zero-config Flyway
- The unspoken power of Qute type-safety
Stop writing boilerplate. buff.ly/aPmLiHC
#Java #Quarkus #DeveloperExperience
Reposted by Loïc Mathieu
Digging into more of the implementation details with @kestra.io! Follow along on my learning journey as I build my first flow. dev.to/missamarakay...
My First Flow with Kestra.io
My thoughts and experience building a small PoC with Kestra.io.
dev.to
January 5, 2026 at 2:24 PM
Digging into more of the implementation details with @kestra.io! Follow along on my learning journey as I build my first flow. dev.to/missamarakay...
Reposted by Loïc Mathieu
🚀 Kestra 1.2 is live!
📦 Assets (EE)
🧩 Templated Blueprints (EE)
📂 Namespace file versioning
🔁 Concurrent triggers
✅ Checks
🎨 UI redesign
☁️ AWS & Azure Marketplace
🧩 Many new plugins
Release post in comments👇
📦 Assets (EE)
🧩 Templated Blueprints (EE)
📂 Namespace file versioning
🔁 Concurrent triggers
✅ Checks
🎨 UI redesign
☁️ AWS & Azure Marketplace
🧩 Many new plugins
Release post in comments👇
January 13, 2026 at 3:24 PM
🚀 Kestra 1.2 is live!
📦 Assets (EE)
🧩 Templated Blueprints (EE)
📂 Namespace file versioning
🔁 Concurrent triggers
✅ Checks
🎨 UI redesign
☁️ AWS & Azure Marketplace
🧩 Many new plugins
Release post in comments👇
📦 Assets (EE)
🧩 Templated Blueprints (EE)
📂 Namespace file versioning
🔁 Concurrent triggers
✅ Checks
🎨 UI redesign
☁️ AWS & Azure Marketplace
🧩 Many new plugins
Release post in comments👇
Reposted by Loïc Mathieu
Tired of your tests misbehaving? Join @loicmathieu.fr on an insightful journey to tackle flaky tests head-on. A must-read for every developer! #coding #testing #foojay
foojay.io/today/flaky-...
foojay.io/today/flaky-...
foojay – a place for friends of OpenJDK
foojay is the place for all OpenJDK Update Release Information. Learn More.
foojay.io
January 13, 2026 at 1:43 PM
Tired of your tests misbehaving? Join @loicmathieu.fr on an insightful journey to tackle flaky tests head-on. A must-read for every developer! #coding #testing #foojay
foojay.io/today/flaky-...
foojay.io/today/flaky-...
Reposted by Loïc Mathieu
Télécommandes, sous-titres, livres audio, pailles, épluche-légumes, SMS… Ces innovations sont d’abord pensées pour les personnes handicapées avant d’être adoptées par tout le monde.
Je raconte leur histoire dans mon dernier article : emmanuelle-aboaf.netlify.app/blog/article...
Je raconte leur histoire dans mon dernier article : emmanuelle-aboaf.netlify.app/blog/article...
Quand les innovations pensées pour les personnes handicapées deviennent universelles - Portfolio d'Emmanuelle ABOAF, développeuse sourde
Il y a des inventions qui, à l’origine, ont été imaginées pour répondre aux besoins spécifiques des personnes handicapées, avant de devenir des outils du quotidien pour tout le monde. Les SMS, la télé...
emmanuelle-aboaf.netlify.app
January 12, 2026 at 11:34 AM
Télécommandes, sous-titres, livres audio, pailles, épluche-légumes, SMS… Ces innovations sont d’abord pensées pour les personnes handicapées avant d’être adoptées par tout le monde.
Je raconte leur histoire dans mon dernier article : emmanuelle-aboaf.netlify.app/blog/article...
Je raconte leur histoire dans mon dernier article : emmanuelle-aboaf.netlify.app/blog/article...
Reposted by Loïc Mathieu
Micronaut announces plans to join Commonhaus 🎉
We look forward to welcoming @micronautfw.bsky.social as a member project. Stay tuned!
micronaut.io/2026/01/12/m...
We look forward to welcoming @micronautfw.bsky.social as a member project. Stay tuned!
micronaut.io/2026/01/12/m...
Micronaut Announces Plans to Join the Commonhaus Foundation - Micronaut Framework
Today, we are announcing that the Micronaut framework is applying to join the Commonhaus Foundation. This is an exciting new step in the Micronaut project’s journey, and we’re looking forward to the o...
micronaut.io
January 13, 2026 at 6:33 AM
Micronaut announces plans to join Commonhaus 🎉
We look forward to welcoming @micronautfw.bsky.social as a member project. Stay tuned!
micronaut.io/2026/01/12/m...
We look forward to welcoming @micronautfw.bsky.social as a member project. Stay tuned!
micronaut.io/2026/01/12/m...
Reposted by Loïc Mathieu
Wouldn't it be great to have a Foojay page on Wikipedia? Who is an experienced Wikipedia author and can help us improve this draft to make it valid for publishing?
en.wikipedia.org/wiki/Draft:F...
en.wikipedia.org/wiki/Draft:F...
Draft:Foojay (Friends Of OpenJDK) - Wikipedia
en.wikipedia.org
January 9, 2026 at 3:46 PM
Wouldn't it be great to have a Foojay page on Wikipedia? Who is an experienced Wikipedia author and can help us improve this draft to make it valid for publishing?
en.wikipedia.org/wiki/Draft:F...
en.wikipedia.org/wiki/Draft:F...
Reposted by Loïc Mathieu
OpenJDK is faster than GraalVM*
It's around twice as fast in one particular area. Read more in my latest tiny blog post at mostlynerdless.de/blog/2026/01...
It's around twice as fast in one particular area. Read more in my latest tiny blog post at mostlynerdless.de/blog/2026/01...
OpenJDK is faster than GraalVM Java* - Mostly nerdless
OpenJDK is faster than GraalVM in some instances, but maybe it's not important? Discover more in this short blog post.
mostlynerdless.de
January 9, 2026 at 8:11 AM
OpenJDK is faster than GraalVM*
It's around twice as fast in one particular area. Read more in my latest tiny blog post at mostlynerdless.de/blog/2026/01...
It's around twice as fast in one particular area. Read more in my latest tiny blog post at mostlynerdless.de/blog/2026/01...
Reposted by Loïc Mathieu
tailwindcss en péril ? 75 % des équipes techniques ont été virés www.programmez.com/actualites/t...
Tailwind CSS licencie 75 % des équipes techniques et ne peut pas rivaliser avec les LLM
Adam Wathan, créateur du populaire Tailwind CSS, a confirmé que 75 % des équipes techniques ont été licenciés cette semaine. La raison invoquée est simple : l'impact brutal de l'IA sur le modèle écono...
www.programmez.com
January 8, 2026 at 12:39 PM
tailwindcss en péril ? 75 % des équipes techniques ont été virés www.programmez.com/actualites/t...