Ruby has been fast enough for 13 years

If nothing else, I think reminding people that what they're "looking to do" (whatever that is) most likely is something they can do in whichever language they choose, and to somehow shoehorn themselves into a language or a set of languages, not because they have a concrete need to, but because they think they might need to... (Once they start... If they ever get going on it...) is foolish and really does not contribute to execution.

Sometimes it's better to get going in the most productive language you can find for the problem space and make a slow/inefficient implementation with few lines of code, minimizing the risk of bugs, (call it "MVP" or whatever) if only to find out whatever it is you're trying to do. Most languages without suffocating boilerplate will do just fine for this, regardless of their performance.