Specifically for Cucumber?

I'd say no. If I start to comment on languages I like and don't, etc. it will not be from a 'cucumber' perspective. It's really tempting to extols the attributes of one language or a paradigm (disclosure I'm an untyped Ruby / Python fan) but I don't think it is very relevant, again, to Cucumber specifically.

So my advice comes from:

• What is used in your workplace, your community, your friends ?
• What is popular and trending so you can get lost of advice to problems ?
• What language will be of most benefit to your career in the future ?

Given this I would generally recommend Python and Javascript as good languages to focus on. Python for back end and more traditional UI testing with Selenium and Javascript, using Jasmine, Jest, etc. for the plethora of js libraries currently on the landscape. I would choose Python over Ruby due to gaining/waning interest in the two (Ruby waning, Python gaining). I base this on the data in the Stack Overflow Annual Surveys

Another viewpoint is: Black Box or White Box testing.

If Black Box, ruby languages less, if white box (internal code or access points are known/exposed) then the application code language would be more relevant.

Specifically for Cucumber?

I'd say no. If I start to comment on languages I like and don't, etc. it will not be from a 'cucumber' perspective. It's really tempting to extols the attributes of one language or a paradigm (disclosure I'm an untyped Ruby / Python fan) but I don't think it is very relevant, again, to Cucumber specifically.

So my advice comes from:

• What is used in your workplace, your community, your friends ?
• What is popular and trending so you can get lost of advice to problems ?
• What language will be of most benefit to your career in the future ?

Given this I would generally recommend Python and Javascript as good languages to focus on. Python for back end and more traditional UI testing with Selenium and Javascript, using Jasmine, Jest, etc. for the plethora of js libraries currently on the landscape. I would choose Python over Ruby due to gaining/waning interest in the two (Ruby waning, Python gaining). I base this on the data in the Stack Overflow Annual Surveys

Another viewpoint is: Black Box or White Box testing.

If Black Box, the language will matter less. If white box (internal code or access points are known/exposed) then the application code language would be more relevant and there would be many communication benefits to using the same language.