[lucasarruda]

Start based on the project itself.

If it's a personal project and there are no risks involved, it's a change to pick a new, innovative or trendy language, like Go, Elixir, Clojure, Rust, etc.

If it's a personal project, but you want to complete it fast, probably pick whatever you are more comfortable with. Don't try a new environment if you have to deliver in time.

If it's a corporate project and chances you are not alone in that project, pick whatever is more comfortable for the team. Don't try to innovate that much or you have a chance of have a world of not predicted problems with that language/environment.

But if it's a corporate project and you are mostly alone, then you could pick a different language from that world. Some language that you have deeper knowledge that others and maybe you wanted the team to try/adopt. And that's a quite nice opportunity to both showcase you abilities, initiative and the language itself - because companies generally have a hard time adopting new things.