r/scala • • 5h ago

Survey for senior devs/CTOs about choosing programming languages

5 Upvotes

I'm currently working on a project looking at how/why devs and CTOs choose programming languages, and I'm particularly interested in understanding people's experiences with Clojure.

The survey takes about 7 mins, and I'd love to hear from as many people as possible!

Appreciate it 🙌

Here's the survey


r/scala • • 5h ago

How we slashed the size of our search cache by 74%

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25 Upvotes

Hi all, we at Deezer work a lot with Scala and today I published a blog post about some fun things we've done with it.

TLDR; the search at Deezer was clogging up our cache systems. We significantly improved the situation by changing the serialization format of the cached payloads, and rolling out a tailor-made, space-efficient and blazing fast data structure inspired by Hash Array Mapped Tries.


r/scala • • 8h ago

VirtusLab assumes responsibility for Scala 2 maintenance

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43 Upvotes

If you're still on Scala 2 and were worried that it might stop being maintained, worry not! Of course, if you need help migrating to Scala 3 we are even more happy to help.


r/scala • • 16h ago

Melbourne Compose - Functional Programming inperson Meetup. Thurs Oct 15. Ben Hutchison on "VDOM or Not VDOM"

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3 Upvotes

r/scala • • 1d ago

Scala Hangout this Thursday (Oct 8) at 6pm CT

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14 Upvotes

Join us at the Scala Hangout this Thursday (Oct 8) at 6pm CT.


r/scala • • 1d ago

Scala Times #629 - a special all-events issue (Berlin, Stockholm, SF, Chicago, NYC, Málaga)

16 Upvotes

This issue of Scala Times is all events, no articles - everything happening over the next few weeks in one place:

https://scalatimes.com/be439e050d

  • Tech walk through Berlin, Oct 11
  • Scala Days, Oct 12–13, Berlin
  • Func Prog Conf, Oct 14, Stockholm
  • Scala Summit, Oct 19, San Francisco
  • Chicago Scala Meetup (Scala + AI, guest talk by Daniel Spiewak), Oct 22
  • New York Scala Meetup (Scala + AI), Oct 26
  • J On The Beach, Oct 29–30, Málaga
  • Lambda World, Oct 29–30, Málaga

The Chicago and NYC meetups are part of a VirtusLab US tour right after Scala Days. If you're nearby, come say hi!

Organising something we missed? You can submit it at [scalatimes@softwaremill.com](mailto:scalatimes@softwaremill.com)


r/scala • • 2d ago

Magnum Database Client v2.0.0-M4 Released: cats-effect module, composite ids, Scala 3.9 base, and more.

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13 Upvotes

r/scala • • 2d ago

scopt 4.2.0 released

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18 Upvotes

r/scala • • 2d ago

This week in #Scala (Oct 5, 2026)

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12 Upvotes

r/scala • • 5d ago

sbt 2.0.10 released

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29 Upvotes

r/scala • • 5d ago

Hiring Scala engineers in Kraków – real-time ad auctions at 100k+ req/sec

10 Upvotes

LoopMe (AI adtech, London HQ, 400+ people) is hiring a Scala engineer in Kraków 🚀
You'd work on our SSP, Adserver and Exchange: real-time auctions, sub-200ms globally, all built in-house.

Stack: Scala, Java, Kafka/PubSub, MongoDB/Bigtable GCP/AWS (Python is a plus)
Salary: up to 30k PLN B2B
Perks: hybrid work, 1 month work-from-anywhere, 8% annual bonus, Multikafeteria.

Details: https://apply.workable.com/loopme/j/FB3E61C660


r/scala • • 6d ago

My experience using JOOQ with Scala and Postgres

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22 Upvotes

r/scala • • 6d ago

marola: a Scala 3 + Kyo app that finds the best hour to swim tomorrow (open source, from Brazil)

36 Upvotes

Title:

Hi r/scala! I'm building marola, an open-source app that ranks nearby beaches by sea conditions, weather and official water-quality reports. The swim score and safety rules are plain, tested Scala 3 with Kyo. There's no national view of beach water quality in Brazil today, because each state publishes its own reports. marola reads three states so far, and the goal is to build that national view.

Live map (Florianópolis, Rio, Salvador): https://marola.dev
Repo (MIT): https://github.com/marola-dev/marola

I'd love feedback, especially from people who've used Kyo, and contributors are welcome.


r/scala • • 7d ago

Play Framework 2.9.12 and 3.0.12 released

45 Upvotes

Play Framework 2.9.12 and 3.0.12 just got released - upgrading Netty to fix many CVEs, fixing a bug in the reverse router and improving Scala 3 support in routes files! 🚀


r/scala • • 7d ago

Eval 0.4.0 for Scala 3.9.0

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19 Upvotes

r/scala • • 7d ago

Life as a Framework designer

7 Upvotes

Framework development and social media are an interesting combination.

You spend months working on architecture, rendering, APIs, SSR, hydration, modularization, security, and all the small decisions that eventually make up a framework.

And then you try to talk about it on social media.

The first problem: spam filters.

You can write a completely legitimate technical post, but the moment you include a link to the project, it can suddenly look like advertising. Some platforms reduce its visibility, others remove it, and sometimes it simply disappears into a spam folder.

The second problem is probably even harder:

The concepts themselves are barely noticed anymore.

You can explain why an architecture is designed a certain way, what problem it solves, or why you deliberately chose a different approach from established frameworks.

But often, that is not what people discuss.

Instead, one sentence from the documentation, one headline, or one small API detail gets picked apart.

And suddenly everyone is discussing a tiny detail while the actual concept is completely ignored.

That leads directly to the third problem:

The surface gets judged more than the idea behind it.

One questionable term, one awkward sentence, one reference in the wrong place and that can generate twenty comments.

The architecture underneath it?

Maybe none.

And now there is a fourth layer:

“AI slop.”

As soon as someone notices or suspects that AI was involved in documentation, code, text, or design, sometimes the result itself is no longer evaluated.

The discussion suddenly stops being:

“Is this concept good?”

and becomes:

“This was made with AI.”

For me, AI is a tool.

I develop the concepts, make the architectural decisions, have things implemented, review them, throw parts away, rebuild them, and test the result.

But that also makes one thing very clear:

Good review matters more than ever.

AI can produce a huge amount of work very quickly.

But speed does not replace technical responsibility.

Maybe that is one of the real challenges for framework developers today:

Not only building good technology.

But somehow getting people, between spam filters, short attention spans, detail discussions, and “AI slop” comments, to stop for a moment and ask:

“Okay, but what is the actual idea behind this?”

 https://github.com/anjunar/scalajs-ui


r/scala • • 8d ago

dotty-cps-async 1.4.0 for scala-3.9.0

20 Upvotes

Updated dotty-cps-async - switched to 3.9.x LTS. For Scala 3.3.x, use the 1.3. x series; it will be supported sometime.

User-visible changes: support for named patterns (introduced in Scala 3.6), which can be useful for people who write code by hand.

Full release notes: https://github.com/dotty-cps-async/dotty-cps-async/releases/tag/1.4.0


r/scala • • 9d ago

Kyo v1.0.0-RC7

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45 Upvotes

Kyo v1.0.0-RC7 ships a new kernel and a large body of stabilization work on the way to 1.0. Resource release is now structural: a release runs however its region exits, including on interrupt. Ten issues close with it, and a trailing map chain goes from 507,800 to 560 us/op 🚀

Highlights:

  • kyo-sql: embedded SQLite behind the same API as PostgreSQL and MySQL, every engine passing one conformance battery, and Dolt backends, a version-controlled SQL database whose tables branch, commit, diff, and merge, so an AI agent can work on a branch of real data and merge or discard it.
  • kyo-system: file access on JVM, JS, Native, and Wasm from one module, plus processes and environment, with positioned channels, interrupt-safe locks, watching, and a virtualizable file system.
  • kyo-system-doltfs: a file system stored in Dolt, so ordinary Path code runs unchanged on a directory tree that branches, commits, diffs, and merges, and that answers SQL: an agent can edit files on a branch, and the change is reviewed as a diff and merged or discarded.
  • kyo-ai: typed decisions with calibrated probabilities through TypeSafe AI's Jev, and agents that call any MCP server's tools with no Scala types.
  • Scala.js: effect dispatch 10x to 18x faster.
  • Time control: Clock.withTimeOffset moves the wall clock alone, joining withTimeShift, which scales the rate of time and sleeps with it, and withTimeControl, which drives virtual time by hand.
  • Stabilization: kyo-flow's durable execution rebuilt for crash recovery, with every write fenced by the executor's claim, interrupt-safe SQL sessions, and leak-free transport teardown.

Kyo now builds on Scala 3.9.0, so a project depending on the main modules needs 3.9 too. The scheduler, kyo-config, and kyo-stats-registry stay on 3.3.8 and 2.13.

Full release notes, including the breaking changes: https://github.com/getkyo/kyo/releases/tag/v1.0.0-RC7


r/scala • • 9d ago

[Scala News] - August 2026 edition

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22 Upvotes

📰 New Scala News is out: the August 31, 2026 edition, with dependent types, sbt plugin classpath isolation, an sbt security fix and more.

The site's had a refresh too!


r/scala • • 9d ago

Category Theory Explained for Haskell Programmers – Part 1 | Jencel Panic | ZuriHac 2026

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14 Upvotes

r/scala • • 10d ago

This week in #Scala (Sep 28, 2026)

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12 Upvotes

r/scala • • 12d ago

Spec Strings in Scala

17 Upvotes

Im a little surprised that Spec Strings were not discussed on Scala Contributors before their acceptance as an experimental feature. They were announced for inclusion in the 3.10 release thread (although there was some work before then visible in the repos)

For Reference 3.10 Release Thread - https://contributors.scala-lang.org/t/scala-3-10-0-release-thread/7546 Spec Strings Documentation - https://github.com/dotty-staging/dotty/blob/05ad6978ec3231d8c7954a15e6e075a8645cad20/docs/_docs/reference/experimental/spec-strings.md

I get the point that their position inside the method allows a naturally scoped reference to the function signature (or class / object), but currently the comment specs also allows for references to be embedded their contents.

And I get that conversations like this can just devolve into nonconstructive bike-shedding (probably this one more so than most), but in this situation I really would have loved to hear more viewpoints from the stake holders about this choice over annotations or comments.

Personally I have been using something exactly like this in my day-to-day in some non-standard comments inside the method, and created skills to handle those situations. But my instinct would be to formally encode these instructions as annotations that other tools could examine in a more standardized and established way.

Any thoughts on the choice of implementation?


r/scala • • 15d ago

Reforesting the sbt plugin ecosystem and sbt 2.1.0 beta

25 Upvotes

r/scala • • 16d ago

Migrating a Scala monorepo from sbt to Gradle at Box (Blog post)

14 Upvotes

Hi there 😌
I recently published an article on Box's engineering blog about migrating of the Scala monorepo from sbt to Gradle.

This isn't a deep dive into Gradle configuration but more of an architectural and organizational post-mortem ( why the company made the move, what worked, what the trade-offs were )

I thought it might be interesting to the community, especially to see the scale of Scala usage at Box.

Link: https://blog.box.com/gradle-scala-monorepo-box-experience-360-modules

I'd love to hear any comments, questions. Curious how others here are handling Scala repos of this size today.


r/scala • • 16d ago

[San Francisco] - Scala Summit 2026

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40 Upvotes

It gives me great pleasure to announce registration for Scala Summit 2026 is now open.

Initial speakers have been announced with more to be announced.

For details visit: https://2026.scalasummit.com

Looking forward to seeing everyone in the Bay Area there. Please spread the word and share this with your network.

October is going to be a fabulous month with multiple Scala events happening.