On: An Introduction to Ractors in Ruby

[jbotdev]

You can still use native threads, as long as you’re not expecting them to improve performance with multi-core CPU usage. The main purpose is typically to perform several I/O operations in parallel (e.g. multiple external API calls). That’s why Ruby applications often rely on “worker pools”, which are essentially forks, to scale performance across cores.

Edit: as the sibling comment mentions, that’s part of what Ractor is trying to solve.