Nicolas Kosinski
@nicokosi.bsky.social
🧑💻 I am a developer. When not procrastinating, I like working with peers using #Java
🧪 I also like #Kotlin, #Go, #Rust, #Clojure and #Scala
🇫🇷 I live in France
🐘 Also on Mastodon: https://fosstodon.org/@nicokosi
🧪 I also like #Kotlin, #Go, #Rust, #Clojure and #Scala
🇫🇷 I live in France
🐘 Also on Mastodon: https://fosstodon.org/@nicokosi
Reposted by Nicolas Kosinski
I am really enjoying having some time between contracts at the moment... I just wrote an article about the test desiderata - this has been on my mind to write about for several years at this point! coding-is-like-cooking.info/2025/12/test...
Test Desiderata 2.0 - Coding Is Like Cooking
Kent Beck is one of the original authors of JUnit, an open source tool that kick-started a huge shift in programmer behaviour that I and others have found immensely valuable. In 2019 he published his ...
coding-is-like-cooking.info
December 8, 2025 at 1:47 PM
I am really enjoying having some time between contracts at the moment... I just wrote an article about the test desiderata - this has been on my mind to write about for several years at this point! coding-is-like-cooking.info/2025/12/test...
Reposted by Nicolas Kosinski
Currently dorking out over this graph about child mortality with my brother. Just mind boggling to take in.
December 2, 2025 at 5:00 AM
Currently dorking out over this graph about child mortality with my brother. Just mind boggling to take in.
Reposted by Nicolas Kosinski
this fall I worked with the core Git folks on writing an official data model for Git and it just got merged! I learned a few new things from writing it. github.com/git/git/blob...
git/Documentation/gitdatamodel.adoc at master · git/git
Git Source Code Mirror - This is a publish-only repository but pull requests can be turned into patches to the mailing list via GitGitGadget (https://gitgitgadget.github.io/). Please follow Documen...
github.com
December 2, 2025 at 5:01 PM
this fall I worked with the core Git folks on writing an official data model for Git and it just got merged! I learned a few new things from writing it. github.com/git/git/blob...
Reposted by Nicolas Kosinski
Ever wanted to know what FSCrawler is about? ⤵️
The behind the scene process is at the end of this thread 😉
The behind the scene process is at the end of this thread 😉
November 28, 2025 at 11:13 AM
Ever wanted to know what FSCrawler is about? ⤵️
The behind the scene process is at the end of this thread 😉
The behind the scene process is at the end of this thread 😉
Reposted by Nicolas Kosinski
It's easy to think every #dev should maintain a blog, contribute to open source and have multiple side projects on the go.
You can be passionate about tech without doing any of those things.
As a father, husband and full-timer, I barely have time to brush my teeth sometimes, let alone all that
You can be passionate about tech without doing any of those things.
As a father, husband and full-timer, I barely have time to brush my teeth sometimes, let alone all that
November 16, 2024 at 9:40 PM
It's easy to think every #dev should maintain a blog, contribute to open source and have multiple side projects on the go.
You can be passionate about tech without doing any of those things.
As a father, husband and full-timer, I barely have time to brush my teeth sometimes, let alone all that
You can be passionate about tech without doing any of those things.
As a father, husband and full-timer, I barely have time to brush my teeth sometimes, let alone all that
Reposted by Nicolas Kosinski
The engineer-manager pendulum model no longer accurately reflects how engineering leadership operates.
Most of us aren’t just an IC or a manager. Technology has forced us to live somewhere in the middle.
I wrote about what this actually looks like now:
www.modernleader.is/p/pendulum-r...
Most of us aren’t just an IC or a manager. Technology has forced us to live somewhere in the middle.
I wrote about what this actually looks like now:
www.modernleader.is/p/pendulum-r...
The engineer–manager pendulum is breaking
The hybrid era of engineering leadership is here, and the traditional IC/manager model is no longer suitable.
www.modernleader.is
November 25, 2025 at 3:01 PM
The engineer-manager pendulum model no longer accurately reflects how engineering leadership operates.
Most of us aren’t just an IC or a manager. Technology has forced us to live somewhere in the middle.
I wrote about what this actually looks like now:
www.modernleader.is/p/pendulum-r...
Most of us aren’t just an IC or a manager. Technology has forced us to live somewhere in the middle.
I wrote about what this actually looks like now:
www.modernleader.is/p/pendulum-r...
Reposted by Nicolas Kosinski
Someone told me my posts “sound like AI.”
So I built an AI detector in Java with Quarkus + LangChain4j.
It turns out detection is harder — and more fascinating — than you’d think.
Read the full breakdown ↓
buff.ly/Qm1KYIB
#Java #AI #Quarkus #LangChain4j
So I built an AI detector in Java with Quarkus + LangChain4j.
It turns out detection is harder — and more fascinating — than you’d think.
Read the full breakdown ↓
buff.ly/Qm1KYIB
#Java #AI #Quarkus #LangChain4j
November 22, 2025 at 7:15 AM
Someone told me my posts “sound like AI.”
So I built an AI detector in Java with Quarkus + LangChain4j.
It turns out detection is harder — and more fascinating — than you’d think.
Read the full breakdown ↓
buff.ly/Qm1KYIB
#Java #AI #Quarkus #LangChain4j
So I built an AI detector in Java with Quarkus + LangChain4j.
It turns out detection is harder — and more fascinating — than you’d think.
Read the full breakdown ↓
buff.ly/Qm1KYIB
#Java #AI #Quarkus #LangChain4j
Reposted by Nicolas Kosinski
🎉 Spring Boot 4 is here!🍃
Upgrading doesn’t have to be painful. Moderne + OpenRewrite brings the automation! 🛠️
Learn how to modernize your stack, reduce tech debt, and unlock the latest features in our new blog.
Upgrading doesn’t have to be painful. Moderne + OpenRewrite brings the automation! 🛠️
Learn how to modernize your stack, reduce tech debt, and unlock the latest features in our new blog.
Spring Boot 4 Migration Guide: Faster, Safer, at Scale
Upgrade to Spring Boot 4 faster and with less risk. Learn how OpenRewrite and Moderne automate Java, Jakarta, Spring Framework, and dependency changes at scale.
buff.ly
November 22, 2025 at 8:45 AM
🎉 Spring Boot 4 is here!🍃
Upgrading doesn’t have to be painful. Moderne + OpenRewrite brings the automation! 🛠️
Learn how to modernize your stack, reduce tech debt, and unlock the latest features in our new blog.
Upgrading doesn’t have to be painful. Moderne + OpenRewrite brings the automation! 🛠️
Learn how to modernize your stack, reduce tech debt, and unlock the latest features in our new blog.
Reposted by Nicolas Kosinski
📝 Blogged: "Building a Durable Execution Engine With SQLite"
Exploring the fundamentals of DE, based on a minimal engine built from scratch, using #SQLite as an execution log, and modern #Java (👋 virtual threads).
👉https://www.morling.dev/blog/building-durable-execution-engine-with-sqlite/
Exploring the fundamentals of DE, based on a minimal engine built from scratch, using #SQLite as an execution log, and modern #Java (👋 virtual threads).
👉https://www.morling.dev/blog/building-durable-execution-engine-with-sqlite/
November 20, 2025 at 2:12 PM
Reposted by Nicolas Kosinski
#OpenRewrite 8.67.0 is here! 🛫
🆕 New rewrite-angular, rewrite-react & rewrite-jasperreports
🌱 Spring Boot 4.0 & Spring Batch 6.0 migrations
⚛️ React 19 upgrade recipe with forwardRef removal
🟢 Node.js crypto & util recipes
☕ Migrate all modules and formats for Jackson v3
github.com/openrewrite/...
🆕 New rewrite-angular, rewrite-react & rewrite-jasperreports
🌱 Spring Boot 4.0 & Spring Batch 6.0 migrations
⚛️ React 19 upgrade recipe with forwardRef removal
🟢 Node.js crypto & util recipes
☕ Migrate all modules and formats for Jackson v3
github.com/openrewrite/...
Release 3.19.0 · openrewrite/rewrite-recipe-bom
What's Changed
Incorporates the latest versions of OpenRewrite (v8.67.0), the rewrite-gradle-plugin (v7.21.0), and the rewrite-maven-plugin (v6.24.0) to improve code parsing accuracy and recipe ex...
github.com
November 20, 2025 at 9:13 PM
#OpenRewrite 8.67.0 is here! 🛫
🆕 New rewrite-angular, rewrite-react & rewrite-jasperreports
🌱 Spring Boot 4.0 & Spring Batch 6.0 migrations
⚛️ React 19 upgrade recipe with forwardRef removal
🟢 Node.js crypto & util recipes
☕ Migrate all modules and formats for Jackson v3
github.com/openrewrite/...
🆕 New rewrite-angular, rewrite-react & rewrite-jasperreports
🌱 Spring Boot 4.0 & Spring Batch 6.0 migrations
⚛️ React 19 upgrade recipe with forwardRef removal
🟢 Node.js crypto & util recipes
☕ Migrate all modules and formats for Jackson v3
github.com/openrewrite/...
Reposted by Nicolas Kosinski
Spring Boot 4 looks amazing 🤩🍃 I have implemented OpenRewrite recipes to automate most of the migration process and handle the major breaking changes. You can run them with the Arconia CLI or using the OpenRewrite Gradle/Mavens plugin. Let me know what you think! I'm planning further improvements.
November 20, 2025 at 9:53 PM
Spring Boot 4 looks amazing 🤩🍃 I have implemented OpenRewrite recipes to automate most of the migration process and handle the major breaking changes. You can run them with the Arconia CLI or using the OpenRewrite Gradle/Mavens plugin. Let me know what you think! I'm planning further improvements.
Reposted by Nicolas Kosinski
Cloudflare's outage was caused by an 'unwrap()' call in Rust code, that panics if a Result isn't a success. Don't blame Rust: it's a case of "should never happen", explicitly written in the code, which could have resulted in memory corruption in other languages. blog.cloudflare.com/18-november-...
Cloudflare outage on November 18, 2025
Cloudflare suffered a service outage on November 18, 2025. The outage was triggered by a bug in generation logic for a Bot Management feature file causing many Cloudflare services to be affected.
blog.cloudflare.com
November 19, 2025 at 7:47 AM
Cloudflare's outage was caused by an 'unwrap()' call in Rust code, that panics if a Result isn't a success. Don't blame Rust: it's a case of "should never happen", explicitly written in the code, which could have resulted in memory corruption in other languages. blog.cloudflare.com/18-november-...
Reposted by Nicolas Kosinski
I recently read and shared You’re Wasting Time in #Java Without These 10 Libraries. I commented on it a bit in my newsletter, but given the amount and intensity of reactions, I think a full-blown post is in order.
#Lombok #JUnit #Jackson #SpringFramework #Liquibase #Flyway #SLF4J #Log4J2
#Lombok #JUnit #Jackson #SpringFramework #Liquibase #Flyway #SLF4J #Log4J2
Are you really wasting your time in Java without these 10 libraries?
I recently read and shared You’re Wasting Time in Java Without These 10 Libraries. I commented on it a bit in my newsletter, but given the amount and intensity of reactions, I think a full-blown post ...
blog.frankel.ch
November 16, 2025 at 6:28 PM
I recently read and shared You’re Wasting Time in #Java Without These 10 Libraries. I commented on it a bit in my newsletter, but given the amount and intensity of reactions, I think a full-blown post is in order.
#Lombok #JUnit #Jackson #SpringFramework #Liquibase #Flyway #SLF4J #Log4J2
#Lombok #JUnit #Jackson #SpringFramework #Liquibase #Flyway #SLF4J #Log4J2
Reposted by Nicolas Kosinski
#OpenRewrite 8.66.1 is here! 🚆
🌱 Spring Boot 4.0 migration recipes
🗂 Additional SpringFox conversions
🔐 Severity-based CVE filtering
🍐 Expand Guava to JDK conversions
🎯 Convert external `@InlineMe` annotations into recipes
🐛 Fixed Maven multi-module resource handling
github.com/openrewrite/...
🌱 Spring Boot 4.0 migration recipes
🗂 Additional SpringFox conversions
🔐 Severity-based CVE filtering
🍐 Expand Guava to JDK conversions
🎯 Convert external `@InlineMe` annotations into recipes
🐛 Fixed Maven multi-module resource handling
github.com/openrewrite/...
Release 3.18.0 · openrewrite/rewrite-recipe-bom
What's Changed
Incorporates the latest versions of OpenRewrite (v8.66.1), the rewrite-gradle-plugin (v7.20.0), and the rewrite-maven-plugin (v6.23.0) to improve code parsing accuracy and recipe ex...
github.com
November 12, 2025 at 7:18 PM
#OpenRewrite 8.66.1 is here! 🚆
🌱 Spring Boot 4.0 migration recipes
🗂 Additional SpringFox conversions
🔐 Severity-based CVE filtering
🍐 Expand Guava to JDK conversions
🎯 Convert external `@InlineMe` annotations into recipes
🐛 Fixed Maven multi-module resource handling
github.com/openrewrite/...
🌱 Spring Boot 4.0 migration recipes
🗂 Additional SpringFox conversions
🔐 Severity-based CVE filtering
🍐 Expand Guava to JDK conversions
🎯 Convert external `@InlineMe` annotations into recipes
🐛 Fixed Maven multi-module resource handling
github.com/openrewrite/...
Reposted by Nicolas Kosinski
🧠 My @bdxio.bsky.social talk, Rewriting the Role: Developers in the Age of LLMs, is now a blog series.
Part I is live: Programmers Are Always Doomed… Until They’re Not.
From Fortran to Copilot, every era said “dev is dead.” But we’re still here.
👉 lostinbrittany.dev/en/programmers-are-always-doomed
Part I is live: Programmers Are Always Doomed… Until They’re Not.
From Fortran to Copilot, every era said “dev is dead.” But we’re still here.
👉 lostinbrittany.dev/en/programmers-are-always-doomed
November 7, 2025 at 6:16 PM
🧠 My @bdxio.bsky.social talk, Rewriting the Role: Developers in the Age of LLMs, is now a blog series.
Part I is live: Programmers Are Always Doomed… Until They’re Not.
From Fortran to Copilot, every era said “dev is dead.” But we’re still here.
👉 lostinbrittany.dev/en/programmers-are-always-doomed
Part I is live: Programmers Are Always Doomed… Until They’re Not.
From Fortran to Copilot, every era said “dev is dead.” But we’re still here.
👉 lostinbrittany.dev/en/programmers-are-always-doomed
Reposted by Nicolas Kosinski
DX's latest study into AI-assisted coding says the same as DORA's recent report - AI won’t save you from your (broken) engineering culture.
But it goes further: the biggest gains come from better ways of working, not AI.
Wrote up my analysis here 👇
But it goes further: the biggest gains come from better ways of working, not AI.
Wrote up my analysis here 👇
Findings from DX’s 2025 report: AI won’t save you from your engineering culture | Rob Bowley
blog.robbowley.net
November 5, 2025 at 10:09 AM
DX's latest study into AI-assisted coding says the same as DORA's recent report - AI won’t save you from your (broken) engineering culture.
But it goes further: the biggest gains come from better ways of working, not AI.
Wrote up my analysis here 👇
But it goes further: the biggest gains come from better ways of working, not AI.
Wrote up my analysis here 👇
Just upgraded my 11-year-old MacBookPro to a maintained macOS version, Sonoma (14). 🆙
So far, so good! 😅
Thanks to OpenCore Legacy Patcher! 🥰
dortania.github.io/OpenCore-Leg...
#legacy #macOS #patcher
So far, so good! 😅
Thanks to OpenCore Legacy Patcher! 🥰
dortania.github.io/OpenCore-Leg...
#legacy #macOS #patcher
November 5, 2025 at 6:12 AM
Just upgraded my 11-year-old MacBookPro to a maintained macOS version, Sonoma (14). 🆙
So far, so good! 😅
Thanks to OpenCore Legacy Patcher! 🥰
dortania.github.io/OpenCore-Leg...
#legacy #macOS #patcher
So far, so good! 😅
Thanks to OpenCore Legacy Patcher! 🥰
dortania.github.io/OpenCore-Leg...
#legacy #macOS #patcher
Reposted by Nicolas Kosinski
Exploring how AI changes the cost of good engineering practices.
Some things that used to feel expensive now feel almost free.
📝 www.eferro.net/2025/11/when...
#AI #SoftwareEngineering
Some things that used to feel expensive now feel almost free.
📝 www.eferro.net/2025/11/when...
#AI #SoftwareEngineering
When AI Makes Good Practices Almost Free
Since I started working with AI agents, I've had a feeling that was hard to explain. It wasn't so much that AI made work faster or easier, b...
www.eferro.net
November 3, 2025 at 3:52 PM
Exploring how AI changes the cost of good engineering practices.
Some things that used to feel expensive now feel almost free.
📝 www.eferro.net/2025/11/when...
#AI #SoftwareEngineering
Some things that used to feel expensive now feel almost free.
📝 www.eferro.net/2025/11/when...
#AI #SoftwareEngineering
Reposted by Nicolas Kosinski
#Maven 4 will bring many improvements to the build tool powering millions of Java projects. Learn more about what's new in this @foojay.io podcast with Hervé Boutemy, Guillaume Nodet, and Maarten Mulders. On YouTube www.youtube.com/watch?v=2qiX... and in your favorite #podcast app.
Maven 4 - The Future of Java Build Automation (#81)
YouTube video by Frank Delporte
www.youtube.com
November 1, 2025 at 10:53 AM
#Maven 4 will bring many improvements to the build tool powering millions of Java projects. Learn more about what's new in this @foojay.io podcast with Hervé Boutemy, Guillaume Nodet, and Maarten Mulders. On YouTube www.youtube.com/watch?v=2qiX... and in your favorite #podcast app.
Listening to this cool @changelog.com episode: « We see dead projects »… 👻
🥳 New episode of Changelog & Friends! changelog.am/115
Changelog & Friends #115
It's a FRIGHT...when your record a podcast with dead projects all around. Tech debt, poor choices, timing, market shift, and optimizing for the wrong things are all lurking around waiting to pop out at you! Just don't forget to push record.
changelog.am
November 1, 2025 at 8:42 AM
Listening to this cool @changelog.com episode: « We see dead projects »… 👻
Reposted by Nicolas Kosinski
I wrote a blog post today "The Microskills Theory of Programming": coding-is-like-cooking.info/2025/10/the-...
The Microskills Theory of Programming - Coding Is Like Cooking
How to Succeed with Technical Coaching Software Developers are constantly shifting between activities. It might all be ‘coding’ but when you look more closely there are hundreds of distinct activities...
coding-is-like-cooking.info
October 31, 2025 at 12:08 PM
I wrote a blog post today "The Microskills Theory of Programming": coding-is-like-cooking.info/2025/10/the-...
Reposted by Nicolas Kosinski
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!
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!
October 30, 2025 at 9:48 AM
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!
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!
Reposted by Nicolas Kosinski
📅 We are happy to welcome the French @elastic.co community on November 4th for their next meetup!
Here is what you can expect:
- Elastic update
- "Do MORE with stateLESS Elasticsearch" by @pilato.fr
- "A BBQ on Serverless?" by Stéphane Ngo
➡️ More info & registration: www.meetup.com/fr-FR/elasti...
Here is what you can expect:
- Elastic update
- "Do MORE with stateLESS Elasticsearch" by @pilato.fr
- "A BBQ on Serverless?" by Stéphane Ngo
➡️ More info & registration: www.meetup.com/fr-FR/elasti...
Meetup ElasticFR #99 - Deezer, mar. 4 nov. 2025, 19:00 | Meetup
Merci de penser à libérer vos places minimum la veille de l'évènement, si vous ne pouvez pas venir.
**Agenda**
* Food & drinks
* Ouverture des portes
* Update sur Elastic
www.meetup.com
October 24, 2025 at 2:35 PM
📅 We are happy to welcome the French @elastic.co community on November 4th for their next meetup!
Here is what you can expect:
- Elastic update
- "Do MORE with stateLESS Elasticsearch" by @pilato.fr
- "A BBQ on Serverless?" by Stéphane Ngo
➡️ More info & registration: www.meetup.com/fr-FR/elasti...
Here is what you can expect:
- Elastic update
- "Do MORE with stateLESS Elasticsearch" by @pilato.fr
- "A BBQ on Serverless?" by Stéphane Ngo
➡️ More info & registration: www.meetup.com/fr-FR/elasti...
TIL #uv, the #Python package manager, can run tools in an ephemeral environment... for instance, 'pycowsay'! 🐮
docs.astral.sh/uv/getting-s...
docs.astral.sh/uv/getting-s...
October 30, 2025 at 4:17 AM
TIL #uv, the #Python package manager, can run tools in an ephemeral environment... for instance, 'pycowsay'! 🐮
docs.astral.sh/uv/getting-s...
docs.astral.sh/uv/getting-s...
Reposted by Nicolas Kosinski
Introducing JUnit 6.0.0: a transformative update that unifies versions, elevates minimum requirements to Java 17, and introduces streamlined support for Kotlin suspend tests. Enjoy enhanced testing performance with the new CancellationToken API, built-in JFR listeners and many more—migrate today!
JUnit 6.0.0 Ships with Java 17 Baseline, Cancellation API, and Kotlin suspend Support
Introducing JUnit 6.0.0: a transformative update that unifies versions, elevates minimum requirements to Java 17, and introduces streamlined support for Kotlin suspend tests. Enjoy enhanced testing pe...
www.infoq.com
October 27, 2025 at 7:16 PM
Introducing JUnit 6.0.0: a transformative update that unifies versions, elevates minimum requirements to Java 17, and introduces streamlined support for Kotlin suspend tests. Enjoy enhanced testing performance with the new CancellationToken API, built-in JFR listeners and many more—migrate today!