Recurse Center

Localhost: Julia Evans

rbspy: Building a Ruby profiler

Abstract: Julia Evans has been an avid user of profilers and debugging tools for years. Recently, she realized there's a lot of room for improvement in these tools, leading her to create rbspy, the first Ruby profiler that works on any running Ruby program.

During this talk Julia walks through building a profiler, why profiling a program from outside the process is hard, and the gritty details on how rbspy works.

About Julia: Julia Evans is a programmer and RC alum who lives in Montreal. She's been excited about profiling & debugging tools for years, and has published several zines explaining how to use them. She blogs about what she's learning at