Earlier quoted context omitted.
That's interesting do you have any idea why the mental load jumped? would a static analysis tool working with your type hints help? Or is there many things to consider at once in the system instead of many individual things?
The biggest issue I keep running into is just the concept of data "shape". I love that clojure gives you so much freedom but it can be quite the footgun in a large system because you see that a function expects a map with keys :foo, :bar, and :baz but what are the values for those keys? Spec helps a little bit here for primitive values but for complex nested structures (e.g. {:a [{:b [1 2]} {:c "bar"}]}), it doesn't…
I'm late to the thread, but I've felt the same pain and wrote a library to help deal with the cognitive load of working on "shapes" of data [1].