Join me as we look at how removing 8 lines of code allowed us to speed up some classes of string interpolation by 2x.

This talk will dive into String interpolation: How interpolations are parsed and compiled, and some of the optimisations that are applied to them.

Then we'll see how a change in the Ruby memory layout caused one of these optimisations to degrade performance, how we found the problem and what we did to fix it!