Redmine

Hi all, im currently working on a college project that consists on analyzing an open source project and I chose Redmine. After checking the source code I realised there are some design patterns used in the project but couldnt find any place where you used strategy pattern and it could be a good way of adding functionality without changing the code already made. For example, in issues tab, in pdf/csv export you could add a new way of exporting only adding a new method.

Is there any part of the project where you use this pattern?

Im not experienced with ruby code so sorry if I made any mistakes and thanks for your time.