I'm not sure any other technology stack would have fared much better. Consider that 6 years, 2 months, and 20 days passed between Rails 3.2 and Rails 5.2. That

I'm not sure any other technology stack would have fared much better. Consider that 6 years, 2 months, and 20 days passed between Rails 3.2 and Rails 5.2. That's quite a bit of time for the framework to evolve. Then factor in the customizations from several non-framework dependencies and those added by GitHub. This is an incredible achievement no matter how you slice it.