I have been seeing a lot of discussion comparing Elixir with Ruby for its concurrency features. The point these discussions miss is that Elixir runs on top of ErlangVM which had concurrency built-in as it was developed for running humungous-large-scale telecom systems. Whereas, Ruby was developed by Matz as a Software Language easy to understand and write. Ruby already had concurrency features through threads and fibers since its 1.9 version and Ruby 3 added parallelism features through ractors. This article covers all these 3 in detail and with a lot of code examples related to even AI and ML. Read it here - Understanding Ruby 3.3 Concurrency: A Comprehensive Guide.