The RubyGems Compact Index: What Powers Every bundle install

Three endpoints handle millions of requests per day, yet most Rubyists have never seen them. The RubyGems.org compact index is the hidden API behind every bundle install, powering dependency resolution across the Ruby ecosystem. In this talk, we'll explore how Bundler uses the compact index to resolve dependencies and how RubyGems.org serves it at scale — including improvements like publish cooldowns, smaller native gems, and security warnings.