Well, I did say at least 2 specific things (syntax, explicit types). But maybe approach this a bit differently and talk about what is great in Clojure that is not good in Java: - persistent datastructures that can easily be made transient in specific performance critical cases - consistent syntax - the language itself is a datastructure so manipulating of code is very easy and you have a serialization format (again EDN) basically for free - the REPL - most of the code transfers 1:1 to ClojureScript, that is not the case for Java and JavaScript which are completely different languages and have very different strengths - dynamic types, but out of the box type hinting is available for some corner cases where it improves performance/ makes interoperability a bit clearer and e.g. using clojure.spec you can with some effort make something approaching depend type systems/ very strong tests incl. generative testing - Clojure/ ClojureScript interoperability with the Java/ JavaScript ecosystem - developer productivity - actually performance especially compared to Python/ Perl/ Ruby, very carefully written Java would win microbenchmarks but in Clojure you can probably improve the overall performance of a large codebase because in the same time as you would need with Java you can do many, many iterations more and therefore explore the optimal solution - you can become very proficient in Clojure in about 6 - 12 months where with Java you probably need maybe 3-5x that time to tackle the same problem space

Yes, some of those things are not so specific to Java. If you only care about performance in micro-benchmarks Java would probably win but probably 95% of the problems in the real world are way more complex. Also, good luck writing correct multi-threaded code in Java vs Clojure. Clojure is uniquely positioned for multi-threaded workloads thanks to persistent datastructures, atoms, agents etc.