Rails boot time is a DX metric now. Every restart costs deploys, CI, and human attention. And agents boot apps way more than people. So, our convenient new require-profiler gem shows what happens during boot: requires, Rails initializers, YAML parsing, HTTP calls. Run it, then drop to a sampling profiler for what the tree can’t explain. One 200-component monolith cut development boot time by 40%.

Get in, human: cut Rails boot time with require-profiler and this guide