Selective Test Execution at Stripe: Fast CI for a 50M-line Ruby monorepo

What this post added

This post details the technical implementation of Stripe's Selective Test Execution system, explaining how it leverages code dependency analysis and test impact prediction to minimize the number of tests run for each code change in a 50M-line Ruby monorepo. It discusses the challenges of scaling CI for large codebases and the strategies employed to achieve fast CI by running only a small percentage of tests on average.