Explore effective strategies for debugging critical performance issues in Ruby applications through this 38-minute conference talk from RubyConf 2023. Learn about various profiling tools that provide valuable insights into code execution, helping developers pinpoint and resolve performance bottlenecks. Discover how these profilers can guide further debugging efforts, even when they don't immediately reveal the root cause. Gain practical knowledge from a real-world case study involving the Ruby version upgrade of a large monolithic Rails application, making the concepts more relatable and applicable to your own development challenges.