Honestly, if you're even slightly concerned about Go's memory footprint and optimization then you shouldn't bother digging any further into Ruby.
There's a reason that the DevOps world abandoned Ruby wholesale in the late 2010s (mostly replacing it with Go).
In a world where container orchestration allowed servers to be more fully utilised, it became increasingly obvious that the ancillary tooling (think log shipping or metrics collection) often had a larger memory and CPU footprint than the core service itself.
Formerly popular tools in this class like Sensu or fluentd have either been rewritten or replaced with Go equivalents, and Ruby seems to be more or less dead for new projects outside of the Rails niche.
There's a reason that the DevOps world abandoned Ruby wholesale in the late 2010s (mostly replacing it with Go).
In a world where container orchestration allowed servers to be more fully utilised, it became increasingly obvious that the ancillary tooling (think log shipping or metrics collection) often had a larger memory and CPU footprint than the core service itself.
Formerly popular tools in this class like Sensu or fluentd have either been rewritten or replaced with Go equivalents, and Ruby seems to be more or less dead for new projects outside of the Rails niche.