Rubyists work from a command line, which makes JRuby startup time a critical concern. Traditionally, the JVM has not been optimized for startup, but that's changing. This talk will explore all available options for making a heavy runtime like JRuby start up quickly, from using class data caching services like Hotspot's CDS and OpenJ9's Quickstart to ahead-of-time compilation of JRuby using GraalVM's Native Image. We'll compare approaches and trade-offs.
Delivered on February 1, 2020 at FOSDEM 2020 in Brussels, Belgium