Advanced
Level 3 — Advanced
These lessons cover runtime and compile-time metaprogramming, categories and extension modules, building DSLs, embedding Groovy and script security, concurrency with virtual threads and async/await, command-line automation, Gradle build scripts, Jenkins pipelines, testing with Spock, Grails and Micronaut, performance, tooling and deployment, and best practices. Recommended: the Level 2 lessons, especially closures in depth, builders, and static compilation.