Depends on what the project is for. Is it a personal hobby project? Then maybe it is a chance to try a new stack. I'd recommend something with a more staticall

Depends on what the project is for. Is it a personal hobby project? Then maybe it is a chance to try a new stack. I'd recommend something with a more statically typed language than Ruby so you can get some experience in that. Java and C# are your mild choices. Haskell would be more hardcore. If it is for money or there is a deadline then stick to what you know.