With my company we successfully build and run business applications for more than 225 clients wordwide and more than 420'000 end users. It's mostly used to support complex business processes such as client onboarding processes in a private bank.
The product is divided into two parts: (1) The part which end users see: Software running in a browser which supports the end user in his day to day job. (2) The part which is used to build part 1, which mostly happens through modelling.
To be more concrete: Part 1 of gets built with dragging and dropping screen components (form fields, texts, buttons, layout elements, ...) onto a screen builder. Additionally the right variables get bound to the elements and the screens get linked to a corresponding process.
You can imagine this to be very straight forward for simple applications, let's say a longer form of three steps. But the amount of elements increase when you have to cover many additional cases, when multiple roles with multiple permissions are involved or when the form has 25 steps instead of 3 because the compliance process requires it.
Bottom line, building client software with our product is amazingly straight forward but can also get painfully complex! I envision the product and its UI to be more simple but first, I want to have some evidence, that it's too complex. User testing is difficult because new users just don't understand enough of the context and the software itself and experienced users are - well - experienced enough and "just live" with the complexity.
Is there any way to measure complexity or cognitive load of a software just with going through it by oneself? E.g. counting the number of steps to reach a certain point? Counting the elements user's need to remember at a certain step? ...