Matej Cerny
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matejcerny.bsky.social
Matej Cerny
@matejcerny.bsky.social
160 followers 150 following 450 posts
Functional programming enthusiast with strong foundations in the relational databases world #FP #Scala #Postgres
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Please share so my boss Michal is happy! 😂 Or to spread the word about VirtusLab / SoftwareMill's new podcast! 📢 Or to support local #Scala agencies! 💪 www.youtube.com/watch?v=dcYZ...
Beyond the Commit, Episode 1: Michal Janoušek
www.youtube.com
There are so many great thoughts, to pinpoint just a few:
1️⃣ Tooling is nowhere near other languages
2️⃣ Missing a true "Spring Boot-like" framework
3️⃣ Official docs need real-world examples
4️⃣ The persistent misconception that "you need async for performance"
#scala youtu.be/a-uME7QBlxg
YouTube
Haoyi Li is a software engineer and a core contributor to the Scala ecosystem. He's built a whole suite of Scala libraries under the com.lihaoyi banner, focusing on simplicity and productivity, as well as the Mill build tool, which he has since expanded beyond Scala to support other JVM tools like Java and Kotlin and experimental support for other things like TypeScript and Android, and promises better performance and user friendliness than Gradle and Maven can ever match. He's also the author of the book Hands-on Scala Programming, which focuses on getting things done with Scala. My own course, Scala Projects, uses Haoyi's book examples as starting points for full-fledged, shippable projects that you can use for yourself or turn into products: https://rockthejvm.com/courses/scala-projects Timeline 0:00 Intro 1:08 Conference tour 8:20 Haoyi's work on Mill 13:55 What Mill does better than other tools 18:48 Picking a config language 21:53 Scala at scale at Databricks 29:20 How Scala can continue innovating 34:50 Increasing industry adoption of Scala 39:45 Misconceptions about Scala 42:39 Haoyi's experience switching between IC - tech lead - manager - IC 49:39 How Haoyi started programming and why Scala stood out 57:08 Scala differentiators for the future 1:01:05 How Haoyi maintains his OSS library ecosystem 1:06:43 Hands-On Scala Programming: writing, publishing, open-sourcing 1:14:40 Haoyi's current and future contributions to Scala 1:18:16 Discussion on AI agents 1:29:54 Parting thoughts
youtu.be
This is probably the most complete tutorial on typeclasses in Scala 3, it's basically a short book. Bookmark it, as it has everything: givens, derivation, mirrors, inline defs, macros... you name it. #scala kubuszok.com//2025/sanely...
After years, I came to the same conclusion: it's worth taking the time to use proper test data, even for attributes you don't currently use in your business logic. It'll save you so much time later. etorreborre.blog/dont-look-do...
Don't look down! Look at the data instead!
You might get the same vertigo
etorreborre.blog
The tech industry is creating its own talent crisis. By ditching junior devs for AI hype, companies are just burning out their seniors and killing the future talent pipeline. #ai www.youtube.com/watch?v=DcJ5...
Dev will really suck in a few years...
www.youtube.com
Binary compatibility is a very important topic that every senior should understand. This video, even though it's about Smithy4s, explains concepts for evolving a library's schema in a binary-compatible way. #scala youtu.be/1HFV-tGZVlY
Deep dive: how I added THIS feature to smithy4s (bincompat-friendly mode)
youtu.be
The most comprehensive collection of Scala learning material finally on YouTube. A freaking 283 videos! #scala www.youtube.com/@Ziverge/pla...
Respect to Dylan Halperin for his massive contribution to @http4s! 🚀 His new MultipartReceiver is in the latest version after over a year of review, adding safer, fail-fast file uploads with size limits and no buffering. #scala github.com/http4s/http4...
Release v0.23.33 · http4s/http4s · GitHub
What's Changed http4s-core fix: proxy authorization header instantiation with basic credentials by @tpetillot in #7742 Introduce MultipartReceiver for custom, fail-fast multipart decoding by @dyle...
github.com
I was really looking forward to io_uring in Postgres 18, but it turns out it's not the winning I/O strategy. Worker, the new default, seems to be the best all-around method so far, performing well on all storage types. #postgres planetscale.com/blog/benchma...
Benchmarking Postgres 17 vs 18 — PlanetScale
Postgres 18 brings a significant improvement to read performance via async I/O and I/O worker threads. Here we compare its performance to Postgres 17.
planetscale.com
Java is removing sun.misc.Unsafe, an API which is widely used but was never supported or meant to be public. This is one of the reasons for the adoption of JDK 17 in the upcoming version of Scala, which relies on Unsafe for its lazy val implementation. #java #scala youtu.be/jCbqkMKegmY
JEP Explained. JEP 471: Deprecate the Memory-Access Methods in sun.misc.Unsafe for Removal
YouTube video by IntelliJ IDEA, a JetBrains IDE
youtu.be
💡 Quick tip: Stop parsing Array[String], use @main and get type-safe command-line args directly as function parameters. #scala
If you are able to represent an illegal state in your code, you should rethink your model. Start with these two simple tips 👇 www.yannmoisan.com/make-illegal... #ddd #scala
The first Trezor with a custom-built secure element is out! What a piece of tech - Bluetooth, a special LiFePO battery with Qi2 charging, a display with 520x380 resolution, an aluminium body and an IP54 rating 🤯 #bitcoin trezor.io/trezor-safe-...
Trezor Safe 7 | Bitcoin-only Hardware Wallet With TROPIC01 Chip
Secure your bitcoin with Trezor Safe 7—Bluetooth, high-res color touchscreen & quantum-ready security.
trezor.io
I have my first on-call shift actually 😀
Why use a dedicated k8s operator setup when you can spend two days building your own webhook-based version in Scala? 😂 Anyway, it was a great read! #scala blog.indoorvivants.com/2025-10-20-r...
What a day to have my first on-call shift 😀 #awsoutage
With all the attention on the official Windows release, I completely missed the new settings UI editor. Zed team's velocity is abnormal 🤯
zed.dev Zed @zed.dev · 18d
By default, you'll be greeted by a friendly new window when opening Zed's settings. No more JSON, unless you're into that type of thing!
What a release! 🎉 127 pull requests have been merged from 18 contributors. Check out the feature tour 👇 #scala
New Metals 1.6.3, codename "Osmium", has just been released!

It comes with few interesting new features and we'll take the opportunity to go on a small tour.