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 with Scala Native, and a web service with Scala JVM. We will explore patterns for integrating with JavaScript libraries and with C libraries for image generation and markdown processing, all without leaving the comfort of the language we know and love. Along the way we’ll pick up some patters for designing abstract interfaces that work across platforms.