Interesting - this is the exact problem José Valim cited when creating Elixir: he was working on Rails multi-core performance in 2010 and found that "writing multi-core software, which is software that runs on all cores with Ruby, was not really straightforward."[1] Ruby's GIL meant only one thread executes at a time.

Fleury's arriving at similar conclusions from the C/systems side: make multi-core the default, not an opt-in. Though his approach still requires explicit coordination (LaneIdx(), barriers, range distribution) vs BEAM where the scheduler automatically distributes processes across cores.

Different tradeoffs for different domains, but both are reacting to the same backwards reality where we program single-core-first on multi-core hardware.

[1] https://www.welcometothejungle.com/en/articles/btc-elixir-jo...