I used to be a professional clojure developer, now I write in ReasonML (syntax change of Ocaml) for work. I would say that that the reason type errors do not h

I used to be a professional clojure developer, now I write in ReasonML (syntax change of Ocaml) for work. I would say that that the reason type errors do not hurt Clojure as much as say Javascript is because Clojure data is immutable, and all the common functions operate on collections or sequences. Basically, if you write idiomatic code, you constantly use datatypes that implement the same interface which higher order functions (map, filter, reduce, etc) expect. In contrast, in OCaml for example you have to think whether you are dealing with an Array or a List. Clojure also provides mechanisms to enforce that functions (Macros too with clojure.spec) are applied the correct data parameters (clojure.spec + pre/post conditions). Spec shines when you are integrating with "foreign" data like the results of a HTTP request. In my experience, it is faster to make changes to a project, then test quickly with the clojure repl than it is to spend a lot of time refactoring types. This is especially true when you are experimenting with how to process data a different way... Having to have all types work out at compile time is a real time sink, when mentally you already know how you want to process data.