This talk presents recent updates to Ractor, which enables parallel and concurrent programming on Ruby.

Ractor still lacks fundamental features. For example, we cannot use “require” method and “timeout” methods on non-main Ractors because of synchronization and implementation issues. We will discuss such problems and how to solve them. From a performance point of view, we have introduced the M:N thread scheduler in Ruby 3.3 and we will show the performance analysis with recent improvements.