Building GitHub with Ruby and Rails | The GitHub Blog

Every Monday a scheduled GitHub Action workflow triggers an automated pull request, which bumps our Rails version to the latest commit on the Rails main branch for that day. All our builds run on this new version of Rails. Once all the builds pass, we review the changes and ship it the next day. Starting an upgrade on Monday you will already have an open pull request linking the changes this Rails upgrade proposes and a completed build.This process is a far stretch from how we did Rails upgrades only a few years ago. In the past, we spent months migrating from our custom fork of Rails to a newer stable release, and then we maintained two Gemfiles to ensure we’d remain compatible with the upcoming release. Now, upgrades take under a week. You can read more about this process in this 2018 blog post. We work closely with the community to ensure that each Rails release is running in production before the release is officially cut.