When a person uses his/her expertise with computers to design a new application, he/she is demonstrating the cognitive adaptation called: ?

I believe the answer is Accomodation

In psychology, Accommodation refers to the process to change what you already know in your mind and adjust it to handle new problem.
In the scenario above, that person already had a certain level of knowledge on how a computer should work, and he use that knowledge to create new application that might never thought by other people before.