It is interesting to read the history of Storm from the original author (Nathan Marz) himself: http://nathanmarz.com/blog/history-of-apache-storm-and-lessons-le

It is interesting to read the history of Storm from the original author (Nathan Marz) himself: http://nathanmarz.com/blog/history-of-apache-storm-and-lessons-learned.html http://nathanmarz.com/blog/history-of-apache-storm-and-lesso... Clojure allowed him to build the initial Storm release by himself in only 5 months. > I made all of Storm's APIs in Java, but implemented Storm in Clojure. By keeping Storm's APIs 100% Java, Storm was ensured to have a very large amount of potential users. By doing the implementation in Clojure, I was able to be a lot more productive and get the project working sooner. Also interesting is that Nathan has now founded a startup working on something which sounds like the next evolution of Storm, and he's building it in Clojure again: https://redplanetlabs.com/ https://redplanetlabs.com/ They recently got 5M in funding and are hiring. Building a Clojure team for it. Personally, I feel the Storm 2.0 release rewrite to Java is really just a case of the new maintainers not knowing Clojure very well, and being primarily Java devs, looking for contributions from people using Storm, which tend itself to be mostly Java shops. Clojure is not quick to pick up, and very different from Java, so unlike Scala, Kotlin, C#, Go, etc. Someone with a Java background and no Clojure or Lisp experience won't be able to contribute as easily. And that's fine, and possibly best for Storm's future now that Nathan has moved on. Unless a Clojure dev had stepped up and adopted Storm, this change isn't at all surprising.