Alejandro Serrano Mena
@serranofp.com
👨💻 Researcher @ Kotlin Evolution @ JetBrains
🧙♂️ Passionate about FP (mostly Arrow & Haskell)
📚 Author of 4 books
🧙♂️ Passionate about FP (mostly Arrow & Haskell)
📚 Author of 4 books
Reposted by Alejandro Serrano Mena
🆕 The Kotlin 2.3 what’s new video is out!
Learn from Márton (@zsmb.co) as he showcases the highlights of the new version, including language additions, features that became stable in this release, and improvements across all platforms 👇 https://youtu.be/_6PSSkqwbp8?si=EktCPcBGjmmhD7jK
Learn from Márton (@zsmb.co) as he showcases the highlights of the new version, including language additions, features that became stable in this release, and improvements across all platforms 👇 https://youtu.be/_6PSSkqwbp8?si=EktCPcBGjmmhD7jK
What's New in Kotlin 2.3
YouTube video by Kotlin by JetBrains
youtu.be
January 21, 2026 at 6:08 PM
🆕 The Kotlin 2.3 what’s new video is out!
Learn from Márton (@zsmb.co) as he showcases the highlights of the new version, including language additions, features that became stable in this release, and improvements across all platforms 👇 https://youtu.be/_6PSSkqwbp8?si=EktCPcBGjmmhD7jK
Learn from Márton (@zsmb.co) as he showcases the highlights of the new version, including language additions, features that became stable in this release, and improvements across all platforms 👇 https://youtu.be/_6PSSkqwbp8?si=EktCPcBGjmmhD7jK
Reposted by Alejandro Serrano Mena
Catch up with everything that's new in Kotlin 2.3 in our latest video!
We have some really cool new features (explicit backing fields and unused return value checker!), previously announced features that are stabilizing, neat stdlib updates, and more!
We have some really cool new features (explicit backing fields and unused return value checker!), previously announced features that are stabilizing, neat stdlib updates, and more!
What's New in Kotlin 2.3
Get your KotlinConf ticket today! https://kotlinconf.com/
Kotlin 2.3 is packed with nice updates: new language features like the unused return value checker and explicit backing fields, previously added language features that became stable in this release, new APIs for time and UUID handling in th
www.youtube.com
January 20, 2026 at 8:02 AM
Catch up with everything that's new in Kotlin 2.3 in our latest video!
We have some really cool new features (explicit backing fields and unused return value checker!), previously announced features that are stabilizing, neat stdlib updates, and more!
We have some really cool new features (explicit backing fields and unused return value checker!), previously announced features that are stabilizing, neat stdlib updates, and more!
Reposted by Alejandro Serrano Mena
Here's our overview and links to our initial materials to help you with AGP 9.0 migrations of your Kotlin projects!
blog.jetbrains.com/k...
More to come later still, such as updates in the KMP wizard and in our samples.
blog.jetbrains.com/k...
More to come later still, such as updates in the KMP wizard and in our samples.
Update your Kotlin projects for Android Gradle Plugin 9.0 | The Kotlin Blog
Learn how to migrate your projects to AGP 9.0 by moving to built-in Kotlin and the new Android KMP library plugin.
blog.jetbrains.com
January 16, 2026 at 10:42 AM
Here's our overview and links to our initial materials to help you with AGP 9.0 migrations of your Kotlin projects!
blog.jetbrains.com/k...
More to come later still, such as updates in the KMP wizard and in our samples.
blog.jetbrains.com/k...
More to come later still, such as updates in the KMP wizard and in our samples.
Reposted by Alejandro Serrano Mena
With Kotlin Coroutines, you can build performant and reliable systems. But to do so, you need a solid understanding of the mechanics that govern how they work. Come join my KotlinConf workshop to learn everything you need to know! kotlinconf.com/workshops/
January 13, 2026 at 9:00 AM
With Kotlin Coroutines, you can build performant and reliable systems. But to do so, you need a solid understanding of the mechanics that govern how they work. Come join my KotlinConf workshop to learn everything you need to know! kotlinconf.com/workshops/
Yay, I'll be speaking in @amsterdam.voxxeddays.com! Curious about how early returns are used in Kotlin?
January 12, 2026 at 8:56 AM
Yay, I'll be speaking in @amsterdam.voxxeddays.com! Curious about how early returns are used in Kotlin?
Reposted by Alejandro Serrano Mena
Arrow-kt 2.2.1.1 is out. Release notes: arrow-kt.io/community/bl...
If you're curious about the Arrow-kt, or functional programming in Kotlin be sure to check out the website. It's full of cool sections on resilience, typed errors, coroutines, STM, immutable data, etc.
If you're curious about the Arrow-kt, or functional programming in Kotlin be sure to check out the website. It's full of cool sections on resilience, typed errors, coroutines, STM, immutable data, etc.
Arrow 2.2.1.1 | Arrow
Arrow 2.2.1.1 is out!
arrow-kt.io
December 18, 2025 at 8:14 AM
Arrow-kt 2.2.1.1 is out. Release notes: arrow-kt.io/community/bl...
If you're curious about the Arrow-kt, or functional programming in Kotlin be sure to check out the website. It's full of cool sections on resilience, typed errors, coroutines, STM, immutable data, etc.
If you're curious about the Arrow-kt, or functional programming in Kotlin be sure to check out the website. It's full of cool sections on resilience, typed errors, coroutines, STM, immutable data, etc.
Reposted by Alejandro Serrano Mena
Unused value checker is really awesome! If you've not tried it, it's experimental in Kotlin 2.3.0 and check you didn't forget any computed values.
I.e. it checks if you forgot to call bind(), or flatMap on an Either value and are tossing the result.
Release notes: arrow-kt.io/community/bl...
I.e. it checks if you forgot to call bind(), or flatMap on an Either value and are tossing the result.
Release notes: arrow-kt.io/community/bl...
December 18, 2025 at 8:02 AM
Unused value checker is really awesome! If you've not tried it, it's experimental in Kotlin 2.3.0 and check you didn't forget any computed values.
I.e. it checks if you forgot to call bind(), or flatMap on an Either value and are tossing the result.
Release notes: arrow-kt.io/community/bl...
I.e. it checks if you forgot to call bind(), or flatMap on an Either value and are tossing the result.
Release notes: arrow-kt.io/community/bl...
Arrow 2.2.1 is out! Taking into account the new @kotlinlang.org 2.3, the library is now ready for the “unused value checker” 👷
arrow-kt.io/community/bl...
arrow-kt.io/community/bl...
Arrow 2.2.1.1 | Arrow
Arrow 2.2.1.1 is out!
arrow-kt.io
December 17, 2025 at 7:04 PM
Arrow 2.2.1 is out! Taking into account the new @kotlinlang.org 2.3, the library is now ready for the “unused value checker” 👷
arrow-kt.io/community/bl...
arrow-kt.io/community/bl...
Reposted by Alejandro Serrano Mena
Kotlin 2.3.0 is out! My faves (no order) 😅
- Unused value checker
- Improved Context Sensitive Resolution
- Java 25 Bytecode
- JS suspend function export
- Better Swift Interop
- Explicit backing fields
- New Kotlin Uuid APIs
and there is much more! Check it out: blog.jetbrains.com/kotlin/2025/...
- Unused value checker
- Improved Context Sensitive Resolution
- Java 25 Bytecode
- JS suspend function export
- Better Swift Interop
- Explicit backing fields
- New Kotlin Uuid APIs
and there is much more! Check it out: blog.jetbrains.com/kotlin/2025/...
Kotlin 2.3.0 Released | The Kotlin Blog
The Kotlin 2.3.0 release is out! This version includes new language features, stable ones, and other features now enabled by default. This release also brings tooling updates, performance improvements
blog.jetbrains.com
December 17, 2025 at 9:57 AM
Kotlin 2.3.0 is out! My faves (no order) 😅
- Unused value checker
- Improved Context Sensitive Resolution
- Java 25 Bytecode
- JS suspend function export
- Better Swift Interop
- Explicit backing fields
- New Kotlin Uuid APIs
and there is much more! Check it out: blog.jetbrains.com/kotlin/2025/...
- Unused value checker
- Improved Context Sensitive Resolution
- Java 25 Bytecode
- JS suspend function export
- Better Swift Interop
- Explicit backing fields
- New Kotlin Uuid APIs
and there is much more! Check it out: blog.jetbrains.com/kotlin/2025/...
New @kotlinlang.org language proposal: companion blocks and extensions github.com/Kotlin/KEEP/...
Feedback is more than welcome!
Feedback is more than welcome!
Companion blocks and extensions · Kotlin KEEP · Discussion #467
This is an issue to discuss companion blocks and extensions. The current full text of the proposal can be found here. TL;DR (from the text of the proposal) data class Vector(val x: Double, val y: D...
github.com
December 15, 2025 at 8:16 PM
New @kotlinlang.org language proposal: companion blocks and extensions github.com/Kotlin/KEEP/...
Feedback is more than welcome!
Feedback is more than welcome!
Reposted by Alejandro Serrano Mena
🚨 Today: Kotlin Ecosystem AMA on r/Kotlin
🕒 3:00–7:00 pm CET
Bring your Kotlin questions on language, multiplatform, backend, AI, libraries, docs, user research, and more 👇
https://kotl.in/reddit-ama
🕒 3:00–7:00 pm CET
Bring your Kotlin questions on language, multiplatform, backend, AI, libraries, docs, user research, and more 👇
https://kotl.in/reddit-ama
December 11, 2025 at 12:47 PM
🚨 Today: Kotlin Ecosystem AMA on r/Kotlin
🕒 3:00–7:00 pm CET
Bring your Kotlin questions on language, multiplatform, backend, AI, libraries, docs, user research, and more 👇
https://kotl.in/reddit-ama
🕒 3:00–7:00 pm CET
Bring your Kotlin questions on language, multiplatform, backend, AI, libraries, docs, user research, and more 👇
https://kotl.in/reddit-ama
Reposted by Alejandro Serrano Mena
Goodbye K1 mode! 👋
IntelliJ IDEA 2025.3 deprecates Kotlin K1.
K2 now powers the IDE via the Kotlin Analysis API.
This means:
⚡ Faster analysis on large projects
🧱 Stable foundation for evolving Kotlin support
🛠️ Improved stability
More in the blog 👇
blog.jetbrains.com/idea/2025/12...
IntelliJ IDEA 2025.3 deprecates Kotlin K1.
K2 now powers the IDE via the Kotlin Analysis API.
This means:
⚡ Faster analysis on large projects
🧱 Stable foundation for evolving Kotlin support
🛠️ Improved stability
More in the blog 👇
blog.jetbrains.com/idea/2025/12...
The Deprecation of K1 Mode | The IntelliJ IDEA Blog
As the next step in the evolution of K2 mode, we are officially deprecating its predecessor, K1 mode.
blog.jetbrains.com
December 10, 2025 at 2:01 PM
Goodbye K1 mode! 👋
IntelliJ IDEA 2025.3 deprecates Kotlin K1.
K2 now powers the IDE via the Kotlin Analysis API.
This means:
⚡ Faster analysis on large projects
🧱 Stable foundation for evolving Kotlin support
🛠️ Improved stability
More in the blog 👇
blog.jetbrains.com/idea/2025/12...
IntelliJ IDEA 2025.3 deprecates Kotlin K1.
K2 now powers the IDE via the Kotlin Analysis API.
This means:
⚡ Faster analysis on large projects
🧱 Stable foundation for evolving Kotlin support
🛠️ Improved stability
More in the blog 👇
blog.jetbrains.com/idea/2025/12...
Reposted by Alejandro Serrano Mena
❓Ask us anything about Kotlin, multiplatform, backend, libraries, docs, education, user research, and Kotlin + AI.
Kotlin Ecosystem Reddit AMA on r/Kotlin
🗓️ Dec 11 · 🕒 3:00–7:00 pm CET
👇 Check out the topics and participants in the thread.
https://kotl.in/dpkmdp
Kotlin Ecosystem Reddit AMA on r/Kotlin
🗓️ Dec 11 · 🕒 3:00–7:00 pm CET
👇 Check out the topics and participants in the thread.
https://kotl.in/dpkmdp
From the Kotlin community on Reddit: Kotlin Ecosystem AMA – December 11 (3–7 pm CET)
Explore this post and more from the Kotlin community
www.reddit.com
December 9, 2025 at 3:33 PM
❓Ask us anything about Kotlin, multiplatform, backend, libraries, docs, education, user research, and Kotlin + AI.
Kotlin Ecosystem Reddit AMA on r/Kotlin
🗓️ Dec 11 · 🕒 3:00–7:00 pm CET
👇 Check out the topics and participants in the thread.
https://kotl.in/dpkmdp
Kotlin Ecosystem Reddit AMA on r/Kotlin
🗓️ Dec 11 · 🕒 3:00–7:00 pm CET
👇 Check out the topics and participants in the thread.
https://kotl.in/dpkmdp
Reposted by Alejandro Serrano Mena
🔍 Curious why we run surveys and interviews, and how your feedback shapes Kotlin?
Natalia Mishina, Paulina Sobieszuk, and Denis Ambatenne join to talk about how our user research works, how we use the results, and why your participation truly matters.
💬 Dec 11 | 3:00–7:00 pm CET | r/Kotlin
Natalia Mishina, Paulina Sobieszuk, and Denis Ambatenne join to talk about how our user research works, how we use the results, and why your participation truly matters.
💬 Dec 11 | 3:00–7:00 pm CET | r/Kotlin
December 9, 2025 at 3:44 PM
🔍 Curious why we run surveys and interviews, and how your feedback shapes Kotlin?
Natalia Mishina, Paulina Sobieszuk, and Denis Ambatenne join to talk about how our user research works, how we use the results, and why your participation truly matters.
💬 Dec 11 | 3:00–7:00 pm CET | r/Kotlin
Natalia Mishina, Paulina Sobieszuk, and Denis Ambatenne join to talk about how our user research works, how we use the results, and why your participation truly matters.
💬 Dec 11 | 3:00–7:00 pm CET | r/Kotlin
Reposted by Alejandro Serrano Mena
Catch @zsmb.co and me hosting some true LEGENDS of the Android now KMP world. You can still RSVP and join to hear from:
- Jake Wharton
- Philipp Lackner
- Zac Sweers
- Russell Wolf
- Marco Gomeiro
- Chris Krueger
- Jake Wharton
- Philipp Lackner
- Zac Sweers
- Russell Wolf
- Marco Gomeiro
- Chris Krueger
Hot take: "In 5 years, the role 'Android Developer' won't exist. We will all be 'Mobile Engineers'." 📉📈
True or just hype?
We’re debating this live with @zacsweers.dev, @zsmb.co, and mobile development experts.
Secure your seat: jb.gg/vbl7v4.
True or just hype?
We’re debating this live with @zacsweers.dev, @zsmb.co, and mobile development experts.
Secure your seat: jb.gg/vbl7v4.
December 3, 2025 at 7:46 AM
Catch @zsmb.co and me hosting some true LEGENDS of the Android now KMP world. You can still RSVP and join to hear from:
- Jake Wharton
- Philipp Lackner
- Zac Sweers
- Russell Wolf
- Marco Gomeiro
- Chris Krueger
- Jake Wharton
- Philipp Lackner
- Zac Sweers
- Russell Wolf
- Marco Gomeiro
- Chris Krueger
Reposted by Alejandro Serrano Mena
In 2 weeks we’re kicking off the Belgium @kotlinlang.org User Group with @sch3lp.bsky.social!
The first session since 2019 😍
We’re starting off with a talk, and afterwards we’ll have an open space.
There’ll will be lots of Kotlin and Kodee goodies 😁 See you there!
www.meetup.com/belgian-kotl...
The first session since 2019 😍
We’re starting off with a talk, and afterwards we’ll have an open space.
There’ll will be lots of Kotlin and Kodee goodies 😁 See you there!
www.meetup.com/belgian-kotl...
Kick-Off Belgian Kotlin User Group, Thu, Dec 11, 2025, 6:30 PM | Meetup
Hi Kotlin enthusiasts!
I am so hyped to be hosting our first BEKUG Meetup at Kunlabora.
This will be an important first time event where we'll welcome you all as members
www.meetup.com
November 28, 2025 at 9:08 AM
In 2 weeks we’re kicking off the Belgium @kotlinlang.org User Group with @sch3lp.bsky.social!
The first session since 2019 😍
We’re starting off with a talk, and afterwards we’ll have an open space.
There’ll will be lots of Kotlin and Kodee goodies 😁 See you there!
www.meetup.com/belgian-kotl...
The first session since 2019 😍
We’re starting off with a talk, and afterwards we’ll have an open space.
There’ll will be lots of Kotlin and Kodee goodies 😁 See you there!
www.meetup.com/belgian-kotl...
Reposted by Alejandro Serrano Mena
We're doing an AMA on /r/Kotlin on December 11th! Prepare your questions, mark your calendars, and join us there in 2 weeks!
www.reddit.com/r/Kotlin/
www.reddit.com/r/Kotlin/
November 27, 2025 at 4:08 PM
We're doing an AMA on /r/Kotlin on December 11th! Prepare your questions, mark your calendars, and join us there in 2 weeks!
www.reddit.com/r/Kotlin/
www.reddit.com/r/Kotlin/
Reposted by Alejandro Serrano Mena
Amper 0.9.0 is out! This release brings a bunch of features that we're excited about:
- First preview of Amper plugins
- Dependency resolution graph caching
- Incremental compilation for Java
- Maven-like layout support
- Auto-sync in the IDE (use IJ 2025.3 Beta)
blog.jetbrains.com/amper/2025/1...
- First preview of Amper plugins
- Dependency resolution graph caching
- Incremental compilation for Java
- Maven-like layout support
- Auto-sync in the IDE (use IJ 2025.3 Beta)
blog.jetbrains.com/amper/2025/1...
Amper Update, November 2025 – Extensibility Preview | The Amper Blog
Amper is an experimental, standalone build tool by JetBrains, for server-side and Kotlin Multiplatform development. Read on for the latest updates!
blog.jetbrains.com
November 24, 2025 at 3:25 PM
Amper 0.9.0 is out! This release brings a bunch of features that we're excited about:
- First preview of Amper plugins
- Dependency resolution graph caching
- Incremental compilation for Java
- Maven-like layout support
- Auto-sync in the IDE (use IJ 2025.3 Beta)
blog.jetbrains.com/amper/2025/1...
- First preview of Amper plugins
- Dependency resolution graph caching
- Incremental compilation for Java
- Maven-like layout support
- Auto-sync in the IDE (use IJ 2025.3 Beta)
blog.jetbrains.com/amper/2025/1...
Reposted by Alejandro Serrano Mena
The @kotlinlang.org DA team @jetbrains.com is looking for a new team member to help promote and collaborate with Kotlin on the server with Spring!
If you're passionate about Kotlin, and Spring this might be just the thing for you.
job-boards.eu.greenhouse.io/jetbrains/jo...
If you're passionate about Kotlin, and Spring this might be just the thing for you.
job-boards.eu.greenhouse.io/jetbrains/jo...
Kotlin Developer Advocate
Amsterdam, Netherlands; Berlin, Germany; Dubai, United Arab Emirates; Limassol, Cyprus; London, United Kingdom; Madrid, Spain; Munich, Germany; Prague, Czech Republic
job-boards.eu.greenhouse.io
November 20, 2025 at 1:39 PM
The @kotlinlang.org DA team @jetbrains.com is looking for a new team member to help promote and collaborate with Kotlin on the server with Spring!
If you're passionate about Kotlin, and Spring this might be just the thing for you.
job-boards.eu.greenhouse.io/jetbrains/jo...
If you're passionate about Kotlin, and Spring this might be just the thing for you.
job-boards.eu.greenhouse.io/jetbrains/jo...
Reposted by Alejandro Serrano Mena
📢 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:
If you love Spring, Kotlin, and their communities, this might just be for you.
Learn more and apply here:
Kotlin Developer Advocate
Amsterdam, Netherlands; Berlin, Germany; Dubai, United Arab Emirates; Limassol, Cyprus; London, United Kingdom; Madrid, Spain; Munich, Germany; Prague, Czech Republic
job-boards.eu.greenhouse.io
November 11, 2025 at 3:25 PM
📢 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:
If you love Spring, Kotlin, and their communities, this might just be for you.
Learn more and apply here:
Reposted by Alejandro Serrano Mena
⏳ Just three weeks left to submit your talk for KotlinConf’26!
👉 https://sessionize.com/kotlinconf-2026/
“Don’t forget that we also accept lightning talks! If you feel like your content would have to be padded to fill a regular session, it might be more enjoyable as a lightning talk.” – @zsmb.co
👉 https://sessionize.com/kotlinconf-2026/
“Don’t forget that we also accept lightning talks! If you feel like your content would have to be padded to fill a regular session, it might be more enjoyable as a lightning talk.” – @zsmb.co
November 10, 2025 at 4:50 PM
⏳ Just three weeks left to submit your talk for KotlinConf’26!
👉 https://sessionize.com/kotlinconf-2026/
“Don’t forget that we also accept lightning talks! If you feel like your content would have to be padded to fill a regular session, it might be more enjoyable as a lightning talk.” – @zsmb.co
👉 https://sessionize.com/kotlinconf-2026/
“Don’t forget that we also accept lightning talks! If you feel like your content would have to be padded to fill a regular session, it might be more enjoyable as a lightning talk.” – @zsmb.co
Taking a break from high level languages 🎮
November 9, 2025 at 1:41 PM
Taking a break from high level languages 🎮
Reposted by Alejandro Serrano Mena
There's less than a month left to submit your talk ideas to KotlinConf 2026! Why not do it today?
KotlinConf 2026: Call for Speakers
KotlinConf is an official conference by JetBrains. It is devoted to the Kotlin programming language and is the place for the community to gather and d...
sessionize.com
November 3, 2025 at 4:07 PM
There's less than a month left to submit your talk ideas to KotlinConf 2026! Why not do it today?
Arrow 2.2.0 is out! arrow-kt.io/community/bl...
- Raise with context parameters
- More DSLs for concurrency,
- "At most once" for Eval,
- New integration with Result4k
- Raise with context parameters
- More DSLs for concurrency,
- "At most once" for Eval,
- New integration with Result4k
Arrow 2.2.0 | Arrow
Arrow 2.2.0 is out, with improved and new functionality.
arrow-kt.io
November 1, 2025 at 4:20 PM
Arrow 2.2.0 is out! arrow-kt.io/community/bl...
- Raise with context parameters
- More DSLs for concurrency,
- "At most once" for Eval,
- New integration with Result4k
- Raise with context parameters
- More DSLs for concurrency,
- "At most once" for Eval,
- New integration with Result4k
Reposted by Alejandro Serrano Mena
The Call for Speakers for KotlinConf 2026 is still open! I'm not exaggerating when I say it's *the* Kotlin event of the year. Please submit to the CFP! Being a speaker is a really exciting way to experience KotlinConf, and share what you know! ❤️ sessionize.com/kotlinconf-2...
October 29, 2025 at 8:48 AM
The Call for Speakers for KotlinConf 2026 is still open! I'm not exaggerating when I say it's *the* Kotlin event of the year. Please submit to the CFP! Being a speaker is a really exciting way to experience KotlinConf, and share what you know! ❤️ sessionize.com/kotlinconf-2...