Ractors have been "experimental" since Ruby 3.0. Four years later, most developers still haven't found a practical use for them.

I did. By moving message deserialization into a Ractor pool, Karafka achieves up to 70% throughput improvement on certain workloads - without requiring users to change a single line of code.

This talk covers the architecture, the patterns that actually perform, and what I learned about making Ractors useful in production.