Practical techniques for getting high-quality results from generative AI.

Our plans for improving Scala's documentation and website, based on community feedback.

The first part of the security audit funded by the Sovereign Tech Fund is done, no critical issues were found.

Schedule, talks and talk submissions for Scala Days 2026

The Call for Proposals for Scala Days 2026 is open until May 31, 2026. Submit talks, interactive labs, or workshops for the conference in Berlin, 12–13 October 2026 (workshops 14–15 October).

During our ongoing work on sbt 2, we discovered and fixed a command injection vulnerability affecting sbt on Windows.

Making your high-level maintainable code as fast as low-level harder-to-read code

We've enabled systematic coverage testing in the Scala 3 compiler's CI pipeline, uncovering and fixing latent bugs that blocked enterprise adoption.

A case study of how sbt-assembly uses sbt2-compat to cross-build for sbt 1 and sbt 2, and a guide of how to use it for your own plugins.

Turn data collection into an experience with Typeform. Create beautiful online forms, surveys, quizzes, and so much more. Try it for FREE.

How the Scala community participated in the recent 2025 Advent of Code challenge

Dependent types greatly improve the expressiveness of the language, allowing to write safer programs and making more illegal states unrepresentable. Scala supports dependent typing for its functional programming constructs — methods and functions. However, when it comes to the object-oriented side o

How many companies miss out on functional languages because they do not know how to find functional programmers? After interviewing engineering leadership at four companies that have used Elm successfully, I found that they all independently chose to hire people without Elm experience and all got th

Automated workflows, such as continuous integration (CI) pipelines, deployment scripts, or cron jobs, are an essential part of any modern software project. There are a plethora of solutions for running these, ranging from classic Jenkins, to more modern solutions such as GitHub actions. These workfl

Typelevel is an ecosystem of projects and a community of people united to foster an inclusive, welcoming, and safe environment around functional programming in Scala. I first started contributing in 2021 and have since watched the seemingly exponential growth of our community and of our tech stack,

Developers love technicalities: type safety, performance, elegant abstractions. But too often, we end up building beautiful systems… that solve the wrong problem. This talk is how we are making Scala a first-class language for boring business software — the kind that actually runs companies and make

“Refactoring Generators” is an interesting approach to generate scala source code. And not only that, but it will also refactor your code if it needs to. Think “git merge” but for scala code. Think scalafix but rules are per file, not global. Core library that does the diff+merge: https://github.co

Rust is primarily known for its ownership-based type system that enables a low-level programming paradigm in a type-safe language. However, another key pillar of Rust is its treatment of unsafe code: while most languages tend to shun unsafe operations, often leaving them poorly specified, Rust gives

Imagine having native support for OpenAPI and/or other API specification languages built into your programming language. By merely importing a specification document, we would obtain a typed interface to a remote service, ready to be used, without the accidental complexity of dealing with HTTP or (d

Level Up: Become a Compiler Engineer (and a Better Programmer) Have you ever wondered what really happens under the hood of your Scala code? Join me for a practical introduction to compiler engineering through the lens of the Scala compiler. Drawing from my two years of experience participating in t

This is going to be a debut talk of sbt 2.0, a Scala 3 rewrite of sbt, which I have been working on for the last few years (in my free time) with the help of Scala Center and other volunteers. Given that sbt 1.x already exists, and it’s the most widely-used build tool in Scala, we wanted to take big

Capture Checking is the next significant feature of Scala, promising a safe and scalable paradigm to write effectful programs using capabilities. Over the past few years, its development has been rapidly progressing, on both theoretical foundations and implementation within the Scala 3 compiler. How

As Netflix expanded, the accumulation of diverse business metrics such as hours streamed, play delay, and rebuffers became increasingly complex, with contributions from a wide array of teams, from Data Scientists to Client Engineers. To address this complexity, Netflix required a centralized solutio

From Paradigms to Percussion: A Beginner’s parallel Journey (and struggles) with Scala and Drums Learning a new programming language can feel overwhelming—so can learning to play a musical instrument. Around the same time I picked up Scala at work, I picked up a pair of drumsticks at home. I didn’t

The object capability model has been established since the 1960s. It is probably the most obvious and clean way to protect trusted from untrusted components in a complex system. Capabilities are a unifying concept for many aspects of programming, including permissions, effects, and resources. They c

Coding the game of unspoken rules in Scala 3 What does it take to create a game where the rules are unknown, constantly evolving, and authored by the players themselves? Inspired by the chaotic and creative card game Mao, we’ve built a multiplayer, browser-based game entirely in Scala 3: backend, f

Request routing is the problem of choosing a function to invoke based on a HTTP request. All but the simplest web frameworks include routing, but that doesn’t mean that routing isn’t an interesting problem. I set out to design a request routing library that was all of: * compositional; * type safe;

Based on my experience developing the Metals Scala language server, I realized that it’s really difficult for most users to unlock it’s full potential. While maintainers are aware of what might be happening and how to solve their issue it’s not so simple for others. In this talk I wanted to describe

Curious about hardware design but think it’s out of reach? This talk proves you can master it with Scala—no prior knowledge needed! We’ll: * Demystify hardware logic design from the ground up, making it accessible to all. * Unveil DFiant HDL (DFHDL), a Scala 3-powered, multi-abstraction hardware de

More and more use cases in parallel and distributed programming are testing the limits of closures. Serializing/pickling closures/functions is incredibly powerful, but full of issues. Using the JVM’s built-in serializer may result in strange outcomes and runtime-errors during deserialization. For ex

Capture Checking is an upcoming feature that brings capability tracking into Scala’s type system, offering a new way to express and control effects in direct style, all without requiring monads or other heavy abstractions. This talk introduces the core ideas behind Capture Checking, how it fits int

In the last few years, one of the leading new areas of development in JetBrains has been AI tooling. It started with simple access to an external Large Language Model within IntelliJ IDEA - but we didn’t stop there. Today, JetBrains offers a wide range of new features and extensions that can make s

We introduced a very specialized Scala 3 project - a high-volume, real-time streaming pipeline for complex traffic data - at a company that does (practically) everything in go. Why would we do that? And would we do it again? In the overall Data Engineering world, go has very little foothold; Python

Ever wondered what Scala sounds like with an electric guitar running through it? We’ll do it live! Few sounds are as iconic as that of an electric guitar played through an overdriven amplifier. Since the first effects pedals hit the market in the early sixties, guitarists have been using them to ta

The power of full-stack Scala: lessons learnt from building an ML platform At NuMind, we build machine learning tools for information extraction using custom-trained language models. But we’re not here to talk about the models—we’re here to talk about the full-stack Scala platform that makes working

Since Scala.js 1.17.0, released in September 2024, users have been able to target WebAssembly for their applications. With a single build tool configuration switch, the Scala.js linker generates WebAssembly code to be used in a JavaScript host. It does so while preserving the semantics of the Scala.

Code generation is one of the most promising applications of large language models (LLMs), offering substantial productivity boosts for developers. However, this benefit is tempered by serious concerns surrounding the correctness and security of the generated code—especially in mission-critical syst

Bazel gives you reproducible, incremental builds at scale—yet many teams still spend hours gardening hand‑written BUILD files. What if your code maintained those files for you? Enter Scala Gazelle. This open‑source Bazel extension scans the import statements already living in your .scala files, res

The direct style in Scala 3, influenced by languages like Kotlin and Rust, simplifies functional programming by eliminating for-comprehension syntax on higher-kinded types. It offers an imperative approach supported by context functions. While many Scala developers support it, others prefer the tra