I was super excited to see this paper released. I've spent time with Python, Java, C#, Javascript and limited time on C and Rust. Clojure was the largest paradigm shifter by a large margin.

Having done concurrent programming in Java, and even implemented some concurrency primitives like semaphores, Clojure was incredible to use. For those that don't know, Clojure uses immutable data structures that mitigate concurrency issues. If you are curious how that's even practical, I highly recommend the paper and also reading about Persistent Data Structures. They reuse shared data, similar to how Git only tracks the delta's between commits, rather than multiple, full copies of the file.

On top of that, you up reducing lines of code by 60-70% of traditional Java or C#.