[black-alert]

Yes it is optional until it gets hard to find a job with typeless Ruby. And indeed split Ruby communities just as with Javascript. The bad thing is that static typing in dynamic languages is HOT, which means if you don't move over to the typed camp you will look old and stupid.

[59nadir]

If anything, dynamically typed languages (without special tooling) is for super smart people or people who are lying to themselves/others about the limitations of the human mind.

But I personally wouldn't hire someone who maintained that dynamic typing produced as good results and was reasonable for an even mid-sized project. They've either never had a long running project or they've never dealt with a big enough code base at that point, or they're simply being dishonest or lack self awareness. None of those are good signals. Not having worked on a project that goes on for long enough is fine, but having opinions on software maintenance in that case is foolish.