As opposed to using JavaScript on the front end & back end? That benefit of JS has always seemed a bit overrated to me—the context for front-end & server-side JS is pretty darn different, too.

Anyway, Ruby & Rails are such a joy to use that, at least for me, the fact that it’s written in a different language than the one we need in the browser is a non-issue.

1) You love the Ruby programming language.

2) It's battle-tested. Tried and true. Batteries included. Can have a web app with most functionality needed running in minutes.

3) There are more reasons, but there are other good options as well. No reason to use Rails if you're not interested in Ruby.

I used to love context switching between frameworks and languages: Rails was more fun and I felt more happier and creative. Django felt more restrictive but I felt more productive. NodeJS was more chaotic but I felt more powerful.

Today I stick with Ruby and Rails. I am trying to do my context switching in the front-end JS frameworks but I just feel a bit dead doing it at the moment!