Optimizing Ruby’s JSON, Part 1 | byroot’s blog

I was recently made maintainer of the json gem, and aside from fixing some old bugs, I focused quite a bit on its performance, so that it is now the fastest JSON parser and generator for Ruby on most benchmarks. Contrary to what one might think, there wasn’t any black magic or deep knowledge involved. Most of the performance patches I applied were fairly simple optimizations driven by profiling. As such, I’d like to go over these changes to show how they are quite generic and that many don’t only apply to C code. But before I dive into these, let me explain why I came about working on this in the first place.