I suggest Clojure too. I have a few years of webservices production experience with Clojure and must say that everything was more than fine. You don't need to

I suggest Clojure too. I have a few years of webservices production experience with Clojure and must say that everything was more than fine. You don't need to work too much with Java (even if you will have to work a little bit with JVM if you plan to support things in production). The toolchain is very good and the community is small, but nice. There are many outstanding production-ready projects; my first hand experience was with: MongoDB, MySQL, RabbitMQ and, of course, web servers, so if your stack includes those, it is definetly a go. I have also tried to deploy Clojure on AWS Lambda and it is definitely possible, even if not sure if it production-grade yet.