I've updated the Ruby 3x3 articles (and slides) collection  @ Planet Ruby.
What's News? Thanks to the RubyElixirConf Tawain new slide decks include:
o The State of / All About Guilds - A New Concurrency Model for Ruby
3 by Koichi Sasada, Cookpad
o Method JIT (Just-In-Time) Compiler for MRI (Matz's Ruby
Interpreter) - Optimizations in Ruby 2.6 Preview 1, 2 by Takashi
Kokubun, Treasure Data.
Anything missing? Additions welcome. Cheers. Prost.