Lightweight Declarative Scala Builds with Mill 1.1.0 & ALPACA

The Kraków Scala Meetup is back!

Join us on March 31st, 2026 at 18:00 in the VirtusLab Office, ul. Szlak 49! Check out what we have lined up

“Lightweight Declarative Scala Builds with Mill 1.1.0” — Haoyi Li

The newest versions of the Mill build tool bring a new declarative configuration API, trading Mill's traditional Scala DSL for an ultra-lightweight YAML configuration to make configuration even simpler than it has been in the past. This talk will explore how Mill's declarative configuration API works, how it interoperates with Mill's traditional programmable configuration, and how we hope it will simplify working with small-scale Scala projects and streamline Scala's getting started experience

Bio: Software Engineer, author of Hands-on Scala Programming.

“ALPACA - a Scala 3 Library for Parser Development” — Bartłomiej Kozak & Bartosz Buczek

ALPACA is a next-generation parser generator that bridges the gap between performance and type-safety. By leveraging Scala 3 metaprogramming, it constructs full LR(1) automata in compile-time with the seamless developer experience of a native Scala library. We will share the story behind the project's origin, compare its architecture with similar solutions, and utilized TASTy reflection to create a parsing engine. Additionally, we’ll dive into the specific metaprogramming hurdles solved: from bypassing the JVM method size limit to managing cross-stage references. To wrap up, we’ll provide a unique perspective on diving straight into Scala’s most advanced features as a newcomer, sharing the experience of building a complex library without prior exposure to the ecosystem.

Bio - Bartłomiej Kozak:

Scala developer at AVSystem. Passionate about metaprogramming, compilers, and type systems. Musical theater enthusiast and specialty coffee enjoyer.

Bio - Bartosz Buczek:

Software engineer at u2i, exploring multiple languages and paradigms beyond his comfort zone. Ice skater and climbing enthusiast outside of work.

See you in Kraków!