Write simulation c# code in "Document Management" which apply all design pattern (at least 20 above)

Hello , I need a developer who can write simulation code in “Document Management” project which apply design pattern, mean that who can build good class to upgrade code in the future.
My requirement : you need to apply all design pattern ( I understand that sometime we do not need design pattern, but for my study you can take example which relevant in my project)
If you are good at in design system , I will send use case document in detail .
Thank you very much !