Scala Days
@scaladays.org
Time to meet again <3
Scala Days 19 - 21 August 2025
EPFL, Lausanne, Switzerland
2025 organizing host: Scala Center
Scala Days 19 - 21 August 2025
EPFL, Lausanne, Switzerland
2025 organizing host: Scala Center
📈 A decade of Scala in production was a big part of the conversation at Scala Days with Kpler. From high-performance systems to data-driven engineering, their presence reflected long-term commitment to building reliable software with Scala.
December 23, 2025 at 3:00 PM
📈 A decade of Scala in production was a big part of the conversation at Scala Days with Kpler. From high-performance systems to data-driven engineering, their presence reflected long-term commitment to building reliable software with Scala.
💡 Audio work in Scala goes deeper than you might expect. This talk explores audio processing using Scala Native and FS2, with a focus on performance and structure.
Check out "Scala and Arpeggio: Audio processing with Scala Native and FS2" from Will Binzi
Check out "Scala and Arpeggio: Audio processing with Scala Native and FS2" from Will Binzi
Will Binzi: Scala and Arpeggio - Audio processing with Scala Native and FS2 [Scala Days 2025]
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
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December 22, 2025 at 7:30 PM
💡 Audio work in Scala goes deeper than you might expect. This talk explores audio processing using Scala Native and FS2, with a focus on performance and structure.
Check out "Scala and Arpeggio: Audio processing with Scala Native and FS2" from Will Binzi
Check out "Scala and Arpeggio: Audio processing with Scala Native and FS2" from Will Binzi
✨ Full-stack Scala sounds nice in theory, but what does it look like in practice? This session shares lessons learned from building a real ML platform end to end.
Here’s "The power of full-stack Scala" by Olga Chuchuk and François Laroche
Here’s "The power of full-stack Scala" by Olga Chuchuk and François Laroche
The power of full stack Scala: lessons learnt from building an ML platform [Scala Days 2025]
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
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December 22, 2025 at 6:09 PM
✨ Full-stack Scala sounds nice in theory, but what does it look like in practice? This session shares lessons learned from building a real ML platform end to end.
Here’s "The power of full-stack Scala" by Olga Chuchuk and François Laroche
Here’s "The power of full-stack Scala" by Olga Chuchuk and François Laroche
🤖 WebAssembly keeps opening new doors for Scala. This session walks through compiling Scala.js to WebAssembly and what that enables.
Check out "Compiling Scala.js to WebAssembly" from Sébastien Doeraene
Check out "Compiling Scala.js to WebAssembly" from Sébastien Doeraene
Sébastien Doeraene: Compiling Scala js to WebAssembly [Scala Days 2025]
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.
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December 22, 2025 at 4:30 PM
🤖 WebAssembly keeps opening new doors for Scala. This session walks through compiling Scala.js to WebAssembly and what that enables.
Check out "Compiling Scala.js to WebAssembly" from Sébastien Doeraene
Check out "Compiling Scala.js to WebAssembly" from Sébastien Doeraene
⚡ Faster feedback cycles were a key theme at Scala Days, and Gradle brought that conversation to sbt users. From build insights to performance metrics, their presence sparked thoughtful discussions around making Scala builds faster and more observable.
December 22, 2025 at 3:00 PM
⚡ Faster feedback cycles were a key theme at Scala Days, and Gradle brought that conversation to sbt users. From build insights to performance metrics, their presence sparked thoughtful discussions around making Scala builds faster and more observable.
🔍 LLMs promise a lot, but can they actually help us write safer code? This talk takes a critical look at using LLMs in Scala with a focus on verification.
Watch "Safe Coding with LLMs: Verifiable Scala Silver Bullet ?" from Andrei Kucharavy
Watch "Safe Coding with LLMs: Verifiable Scala Silver Bullet ?" from Andrei Kucharavy
Andrei Kucharavy: Safe Coding with LLMs - Verifiable Scala Silver Bullet [Scala Days 2025]
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
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December 22, 2025 at 2:31 PM
🔍 LLMs promise a lot, but can they actually help us write safer code? This talk takes a critical look at using LLMs in Scala with a focus on verification.
Watch "Safe Coding with LLMs: Verifiable Scala Silver Bullet ?" from Andrei Kucharavy
Watch "Safe Coding with LLMs: Verifiable Scala Silver Bullet ?" from Andrei Kucharavy
🧪 Large builds get painful fast without good automation. This talk looks at using Scala Gazelle to keep Bazel builds on track with less manual work.
Here’s "From Imports to Targets: Bazel on Autopilot with Scala Gazelle" by Wojciech Mazur
Here’s "From Imports to Targets: Bazel on Autopilot with Scala Gazelle" by Wojciech Mazur
Wojciech Mazur: From Imports to Targets - Bazel on Autopilot with Scala Gazelle [Scala Days 2025]
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
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December 19, 2025 at 7:52 PM
🧪 Large builds get painful fast without good automation. This talk looks at using Scala Gazelle to keep Bazel builds on track with less manual work.
Here’s "From Imports to Targets: Bazel on Autopilot with Scala Gazelle" by Wojciech Mazur
Here’s "From Imports to Targets: Bazel on Autopilot with Scala Gazelle" by Wojciech Mazur
🤖 Direct-style programming can feel elegant until you try to compose it. This session explores what happens when flatMap enters the picture.
Check out "Yo Dawg, Heard You Want To FlatMap Your Direct-Style" from Riccardo Cardin
Check out "Yo Dawg, Heard You Want To FlatMap Your Direct-Style" from Riccardo Cardin
Riccardo Cardin: Yo Dawg, Heard You Want To FlatMap Your Direct Style [Scala Days 2025]
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
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December 19, 2025 at 6:28 PM
🤖 Direct-style programming can feel elegant until you try to compose it. This session explores what happens when flatMap enters the picture.
Check out "Yo Dawg, Heard You Want To FlatMap Your Direct-Style" from Riccardo Cardin
Check out "Yo Dawg, Heard You Want To FlatMap Your Direct-Style" from Riccardo Cardin
🧪 Building APIs for real-world systems comes with constraints. This talk walks through designing and implementing gRPC APIs for autonomous driving in Scala.
Here’s "gRPC APIs for Autonomous Driving from Design to Implementation in Scala" by Bendix Sältz
Here’s "gRPC APIs for Autonomous Driving from Design to Implementation in Scala" by Bendix Sältz
Bendix Sältz: gRPC APIs for Autonomous Driving from Design to Implementation [Scala Days 2025]
gRPC APIs for Autonomous Driving from Design to Implementation in Scala
Introduction
Everyone uses APIs all the time. Some of us integrate with existing APIs. Some of us need to create and implement new APIs for the services we’re working on. This talk follows the story of creating new APIs for int
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December 19, 2025 at 4:30 PM
🧪 Building APIs for real-world systems comes with constraints. This talk walks through designing and implementing gRPC APIs for autonomous driving in Scala.
Here’s "gRPC APIs for Autonomous Driving from Design to Implementation in Scala" by Bendix Sältz
Here’s "gRPC APIs for Autonomous Driving from Design to Implementation in Scala" by Bendix Sältz
✨ Productivity isn’t just about tools, it’s about how you use them. This session looks at the intersection of Scala, developer productivity, and AI.
Here’s "Scala, Productivity, and AI" by Krzysztof Romanowski
Here’s "Scala, Productivity, and AI" by Krzysztof Romanowski
Krzysztof Romanowski: Scala, Productivity, and AI [Scala Days 2025]
Scala is powerful, no doubt—but are we really getting the most out of it when it comes to productivity? In this talk, we’ll explore how to boost not just coding speed, but the entire software development lifecycle—from idea to maintenance. I’ll share what working with dozens of painful Scala project
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December 19, 2025 at 3:00 PM
✨ Productivity isn’t just about tools, it’s about how you use them. This session looks at the intersection of Scala, developer productivity, and AI.
Here’s "Scala, Productivity, and AI" by Krzysztof Romanowski
Here’s "Scala, Productivity, and AI" by Krzysztof Romanowski
🛠️ Tooling and developer experience were front and center at Scala Days with JetBrains. From AI-assisted workflows to hands-on discussions around the IntelliJ Scala Plugin, their booth was a great place to talk Scala, IDEs, and what developers need next.
December 19, 2025 at 3:00 PM
🛠️ Tooling and developer experience were front and center at Scala Days with JetBrains. From AI-assisted workflows to hands-on discussions around the IntelliJ Scala Plugin, their booth was a great place to talk Scala, IDEs, and what developers need next.
🔍 Performance problems often come from patterns that look fine at first glance. This talk explores common Akka anti-patterns and how to avoid them.
Watch "Akka Unplugged" from Lukasz Marchewka
Watch "Akka Unplugged" from Lukasz Marchewka
Lukasz Marchewka: Akka Unplugged the anti-patterns that kill performance [Scala Days 2025]
Akka Unplugged - the anti-patterns that kill performance (and how to fix them)
The mistakes you don’t have to make
Akka is simultaneously one of Scala’s most powerful and most misunderstood technologies. Its flexibility becomes a double-edged sword - enabling developers to solve hard problems easil
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December 19, 2025 at 2:38 PM
🔍 Performance problems often come from patterns that look fine at first glance. This talk explores common Akka anti-patterns and how to avoid them.
Watch "Akka Unplugged" from Lukasz Marchewka
Watch "Akka Unplugged" from Lukasz Marchewka
💡 Small workflow improvements add up fast. This talk digs into IntelliJ IDEA and the Scala plugin, with tips that actually make day-to-day work smoother.
Check out "Boost Your Productivity with IntelliJ IDEA and Scala Plugin" from Dmitrii Naumenko
Check out "Boost Your Productivity with IntelliJ IDEA and Scala Plugin" from Dmitrii Naumenko
Dmitrii Naumenko: Boost Your Productivity with IntelliJ, Scala Plugin and More [Scala Days 2025]
Boost Your Productivity with IntelliJ IDEA and Scala Plugin - and More
In this talk, we will explore practical ways to work more efficiently with IntelliJ IDEA and the Scala Plugin. The focus will be on selected, often underrated capabilities that can noticeably improve workflow and productivity. W
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December 18, 2025 at 7:01 PM
💡 Small workflow improvements add up fast. This talk digs into IntelliJ IDEA and the Scala plugin, with tips that actually make day-to-day work smoother.
Check out "Boost Your Productivity with IntelliJ IDEA and Scala Plugin" from Dmitrii Naumenko
Check out "Boost Your Productivity with IntelliJ IDEA and Scala Plugin" from Dmitrii Naumenko
🔍 How does FP hold up once it leaves the whiteboard? This panel digs into where FP shines, where it struggles, and how it shows up in real teams.
Watch "Panel: Functional Programming And the Real World" from Dimi Racordon and Evan Czaplicki
Watch "Panel: Functional Programming And the Real World" from Dimi Racordon and Evan Czaplicki
Panel: Functional Programming And the Real World [Scala Days 2025]
Panel: Functional Programming And the Real World
with Dimi Racordon, Evan Czaplicki, Martin Odersky & Ralf Jung
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December 18, 2025 at 6:23 PM
🔍 How does FP hold up once it leaves the whiteboard? This panel digs into where FP shines, where it struggles, and how it shows up in real teams.
Watch "Panel: Functional Programming And the Real World" from Dimi Racordon and Evan Czaplicki
Watch "Panel: Functional Programming And the Real World" from Dimi Racordon and Evan Czaplicki
💡 Real-world GenAI gets messy. This talk looks at how streaming, RAG, and real-time systems come together at scale using Scala and FS2.
Check out "LLMs in the Wild: Streaming, RAG, and Real-Time GenAI at Scale with Scala and FS2" from Muayad Sayed Ali
Check out "LLMs in the Wild: Streaming, RAG, and Real-Time GenAI at Scale with Scala and FS2" from Muayad Sayed Ali
Muayad Sayed Ali: LLMs in the Wild - Streaming, RAG, and Real Time GenAI at Scale[Scala Days 2025]
LLMs in the Wild: Streaming, RAG, and Real-Time GenAI at Scale with Scala and FS2
Building GenAI features is one thing—operating them reliably in production is another. In this talk, we’ll dive into how we’ve architected and scaled real-time Generative AI systems using Scala, FS2, and Server-Sent E
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December 18, 2025 at 4:29 PM
💡 Real-world GenAI gets messy. This talk looks at how streaming, RAG, and real-time systems come together at scale using Scala and FS2.
Check out "LLMs in the Wild: Streaming, RAG, and Real-Time GenAI at Scale with Scala and FS2" from Muayad Sayed Ali
Check out "LLMs in the Wild: Streaming, RAG, and Real-Time GenAI at Scale with Scala and FS2" from Muayad Sayed Ali
🌍 For more than a decade, Scalac has been a steady force in the Scala ecosystem. At Scala Days, their focus was on supporting the community, exchanging real-world experience, and exploring how Scala and AI continue to evolve together.
December 18, 2025 at 3:00 PM
🌍 For more than a decade, Scalac has been a steady force in the Scala ecosystem. At Scala Days, their focus was on supporting the community, exchanging real-world experience, and exploring how Scala and AI continue to evolve together.
🧪 Database access often lives at the edge between safety and convenience. This session shows how to build type-safe queries in Scala without relying on macros.
Here’s "Macro-Free Type-Safe Database Queries in Scala" by Anna Herlihy
Here’s "Macro-Free Type-Safe Database Queries in Scala" by Anna Herlihy
Anna Herlihy: Macro Free Type Safe Database Queries in Scala [Scala Days 2025]
In Scala, writing correct and composable database queries requires navigating a crowded design space: solutions range from powerful but opaque libraries that rely on advanced language features like macros and higher-kinded types, to lightweight, flexible, yet error-prone string-based approaches.
Th
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December 18, 2025 at 3:00 PM
🧪 Database access often lives at the edge between safety and convenience. This session shows how to build type-safe queries in Scala without relying on macros.
Here’s "Macro-Free Type-Safe Database Queries in Scala" by Anna Herlihy
Here’s "Macro-Free Type-Safe Database Queries in Scala" by Anna Herlihy
✨ Scala 3 changed the way we think about implicits. This session walks through contextual abstractions and how they reshape everyday Scala code.
Here’s "Say goodbye to implicits - contextual abstractions in Scala 3" by Magda Stożek
Here’s "Say goodbye to implicits - contextual abstractions in Scala 3" by Magda Stożek
Magda Stożek: Say goodbye to implicits - contextual abstractions in Scala 3 [Scala Days 2025]
Have you ever been confused by implicits in Scala? I most certainly have. I struggled to understand them at the beginning of my Scala journey, and to this day I trip over them regularly. It doesn’t help that one keyword can be used for many different things - defining Implicit parameters, implicit c
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December 18, 2025 at 2:37 PM
✨ Scala 3 changed the way we think about implicits. This session walks through contextual abstractions and how they reshape everyday Scala code.
Here’s "Say goodbye to implicits - contextual abstractions in Scala 3" by Magda Stożek
Here’s "Say goodbye to implicits - contextual abstractions in Scala 3" by Magda Stożek
✨ Concurrency doesn’t have to mean tangled abstractions. This session walks through Ox 1.0 and its direct-style approach to concurrency and resiliency.
Here’s "A Tour of Ox 1.0: Direct-Style Concurrency and Resiliency" by Adam Warski
Here’s "A Tour of Ox 1.0: Direct-Style Concurrency and Resiliency" by Adam Warski
Adam Warski: A Tour of Ox 1 0 - Direct Style Concurrency and Resiliency [Scala Days 2025]
Ox provides a toolkit for safe concurrency and resiliency for Scala on the JVM. After two years of prototyping, we’re delighted to showcase the final product. With Ox, you can build and deliver direct-style Scala applications today.
In the code-first presentation, we’ll begin with concurrency (incl
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December 18, 2025 at 1:23 PM
✨ Concurrency doesn’t have to mean tangled abstractions. This session walks through Ox 1.0 and its direct-style approach to concurrency and resiliency.
Here’s "A Tour of Ox 1.0: Direct-Style Concurrency and Resiliency" by Adam Warski
Here’s "A Tour of Ox 1.0: Direct-Style Concurrency and Resiliency" by Adam Warski
🤖 Functional programming isn’t just for software. This talk explores how Scala and FP ideas can be used to compose and structure music.
Check out "Scala, Sound, and Structure: Composing Music through Functional Programming" from Johanna Odersky
Check out "Scala, Sound, and Structure: Composing Music through Functional Programming" from Johanna Odersky
Johanna Odersky: Scala, Sound, and Structure - Composing Music through FP [Scala Days 2025]
Scala, Sound, and Structure: Composing Music through Functional Programming
What do functional programming and Johann Sebastian Bach’s music have in common? More than you’d think. In this talk, we’ll explore how concepts from functional programming—immutability, pure functions, recursion—can be app
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December 17, 2025 at 5:54 PM
🤖 Functional programming isn’t just for software. This talk explores how Scala and FP ideas can be used to compose and structure music.
Check out "Scala, Sound, and Structure: Composing Music through Functional Programming" from Johanna Odersky
Check out "Scala, Sound, and Structure: Composing Music through Functional Programming" from Johanna Odersky
💡 Managing secrets is one of those problems you only notice when it goes wrong. This talk looks at Cryptic and how it helps keep sensitive data under control.
Check out "Cryptic - keeps your secrets" from Odd Möller and Martin Zachrison
Check out "Cryptic - keeps your secrets" from Odd Möller and Martin Zachrison
Odd Möller & Martin Zachrison: Cryptic - keeps your secrets [Scala Days 2025]
Learn how to put encryption at the heart of your handling of sensitive data with Cryptic. You don’t need to put everything in an encrypted data store, implementing elaborate find-and-purge routines for removing sensitive data or use any other intrusive all-or-nothing approach. Instead simply define
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December 17, 2025 at 4:30 PM
💡 Managing secrets is one of those problems you only notice when it goes wrong. This talk looks at Cryptic and how it helps keep sensitive data under control.
Check out "Cryptic - keeps your secrets" from Odd Möller and Martin Zachrison
Check out "Cryptic - keeps your secrets" from Odd Möller and Martin Zachrison
🤖 Cats Effect keeps evolving, and so does its runtime. This talk explores the new integrated I/O runtime and what io_uring brings to async I/O.
Check out "Exploring Cats Effect's New Integrated I/O Runtime: Async I/O with io_uring" from Antonio Jimenez
Check out "Exploring Cats Effect's New Integrated I/O Runtime: Async I/O with io_uring" from Antonio Jimenez
Antonio Jimenez: Exploring Cats Effect’s New Integrated I/O Runtime [Scala Days 2025]
Exploring Cats Effect’s New Integrated I/O Runtime: Async I/O with io_uring
This presentation explores the new Cats Effect I/O integrated runtime and how it leverages kernel interfaces like io_uring to achieve dramatic performance gains.
We will dive into the foundations of this approach: blocking
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December 17, 2025 at 3:00 PM
🤖 Cats Effect keeps evolving, and so does its runtime. This talk explores the new integrated I/O runtime and what io_uring brings to async I/O.
Check out "Exploring Cats Effect's New Integrated I/O Runtime: Async I/O with io_uring" from Antonio Jimenez
Check out "Exploring Cats Effect's New Integrated I/O Runtime: Async I/O with io_uring" from Antonio Jimenez
🤖 AI agents were a big topic at Scala Days, and WRITER brought a strong perspective to the conversation. From enterprise-grade agent building to real-world Scala hiring, their presence sparked great discussions with engineers and teams across the community.
December 17, 2025 at 3:00 PM
🤖 AI agents were a big topic at Scala Days, and WRITER brought a strong perspective to the conversation. From enterprise-grade agent building to real-world Scala hiring, their presence sparked great discussions with engineers and teams across the community.
✨ Sometimes a bit of frustration leads to good questions. This talk looks at what Scala highlighting gets right, what it gets wrong, and why it still matters.
Here’s "Tree Sitting will continue until Scala highlighting improves" by Anton Sviridov
Here’s "Tree Sitting will continue until Scala highlighting improves" by Anton Sviridov
Anton Sviridov: Tree Sitting will continue until Scala highlighting improves [Scala Days 2025]
In this talk we take a problem – accurate Scala syntax highlighting – and build a microcosm of tools around it, relying on industry-proven Tree Sitter grammars and parsers. Good tooling follows you across platforms, locations, and usecases, and so we will build a browser app with Scala.js, a CLI wit
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December 17, 2025 at 2:34 PM
✨ Sometimes a bit of frustration leads to good questions. This talk looks at what Scala highlighting gets right, what it gets wrong, and why it still matters.
Here’s "Tree Sitting will continue until Scala highlighting improves" by Anton Sviridov
Here’s "Tree Sitting will continue until Scala highlighting improves" by Anton Sviridov
🔍 Code gen looks great on paper until it meets the real-world. This talk digs into the practical challenges teams actually face.
Watch "Are You Tall Enough for This Ride? Real-world Challenges in Code Generation" from Michał Pawlik and Jakub Kozłowski
Watch "Are You Tall Enough for This Ride? Real-world Challenges in Code Generation" from Michał Pawlik and Jakub Kozłowski
Are You Tall Enough for This Ride？ Real world Challenges in Code Generation [Scala Days 2025]
Are You Tall Enough for This Ride? Real-world Challenges in Code Generation
He just released a patch release in smithy4s. Little did he know, a “simple bugfix” would turn into a compilation error for several dozen developers, faster than he could say “binary compatibility.”
Our tale of woe begins
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December 17, 2025 at 1:11 PM
🔍 Code gen looks great on paper until it meets the real-world. This talk digs into the practical challenges teams actually face.
Watch "Are You Tall Enough for This Ride? Real-world Challenges in Code Generation" from Michał Pawlik and Jakub Kozłowski
Watch "Are You Tall Enough for This Ride? Real-world Challenges in Code Generation" from Michał Pawlik and Jakub Kozłowski