The word "optimisation" should not be confused with considering computational complexity, and I believe we are in dire need for a catchy word for the latter.
One of the most important steps in programming is:
How many elements could this code actually have to process, and if there could be many: is this datastructure/algorithm suitable for that?
This is almost never premature. This should NOT be called optimisation.
I would like an own word for that. Suggestions?