Audience question on whether Rails is a reliable target for JRuby. Yes — hundreds or thousands of Rails deployments on JRuby; team mostly hears about them only when something breaks. Rails itself has been made thread-safe over years. One current catch: database adapters for Rails 8.0/8.1 aren't officially released yet (almost ready; some users already run them off master). Charles himself followed the conference's MCP workshop on a slightly older Rails and everything worked like C Ruby modulo small config changes. Small Sinatra+SQL apps on JRuby have handled ~10,000 concurrent requests and hundreds of thousands of ops/second.