[nkh]

When type checking is needed, I find the Truss library* does the trick quite well.

As for the syntax, there is very little, which can make it a harder lift but once you have the hang of it you won't deal with the issues identified in the parent comment.

* https://github.com/taoensso/truss

[The_Colonel]

I don't know what Truss is, but I know that I inherited a few smaller Clojure projects / services, and it's untyped hell. Having optional typing means most people are not going to use it.