I loved clojure until working with it for a few years, with some of the famous best teams in Europe and America, including Cognitect people, who ill leave unnamed here.

I fell out of love when I realised what the language is - a mutable, imperative, blocking IO by default language with lambdas and zero guarantees at compile time. Effects happen at any time, as it is an imperative language. Just like JS with a better syntax but with blocking IO and Java threads.

Backends, when more than a handful coders program, turn to runtime checking all the time with spec or schema, and because it’s always up to you to make things async, things often end up depending on a handful of blocking calls. It’s not impossible to write good big programs in clojure, but when working with a group it does not tend to end up that way. Changing a program from sync to async with zero help from the compiler is a task that ends up requiring a lot of time, and negotiation, when it could’ve been the default.

In imperative languages, where you have no control over what effects run, programmers often turn to frameworks to square their program. In teams of >20ppl using clojure, it instead tends to become siloed, where a few people “own” a part of the code, and others must request changes there. It’s not a law of nature, but a pattern I’ve seen emerging in my experience working with clojure teams, including the very famous ones. Time spent negotiating and in these meetings is time wasted.

I should make sure to thank Clojure for getting me into lisp and emacs though, as well as Hickeys enlightening talks.