You have a beginner programmer and you give him to program a solution. You want to know, how much knowledge about a programming language he has. If beginner is working with an IDE, how much knowledge he needs to complete his task?
When you are working on more task on the same time, you will spend on a task more time than, if you were working on tasks sequentially.
When we have mutable shared state, written code is harder to understand. We have to know where the state has become shared and where it is modified. Usually those location are on different places. It become worse, when inner state of a class is shared.
Would we get same software solution, if we hired different teams to build the software solution? How team’s knowledge influence software solution?