Make It Right (Ruby runtime tier). YARV/MRI Ruby 3.3+ runtime reliability footguns shared across EVERY Ruby backend framework (Rails, Sinatra, Hanami, Sidekiq workers) — distinct from the generic backend gates and from any one framework's mechanics. Covers: the GVL (threads give no CPU parallelism,
Make It Right (Ruby runtime tier). YARV/MRI Ruby 3.3+ runtime reliability footguns shared across EVERY Ruby backend framework (Rails, Sinatra, Hanami, Sidekiq workers) — distinct from the generic backend gates and from any one framework's mechanics. Covers: the GVL (threads give no CPU parallelism, like Python's GIL), Puma's forked-worker + thread model, fork-safety of DB/Redis connections, copy-o