Simon Willison’s Weblog

Running GitHub on Rails 6.0. Back in 2019 Eileen M. Uchitelle explained how GitHub upgraded everything in production to Rails 6.0 within 1.5 weeks of the stable release. There’s a trick in here I really
like: they have an automated weekly job which fetches the latest Rails main branch and runs the full GitHub test suite against it, giving them super-early warnings about anything that might break and letting them provide feedback to upstream about unintended regressions.