How we can assure that our Web & mobile application Is GDPR Complaint

Question

Is there anyone who is have great knowledge for data security and who knows data protection act as well. With respect to the web and mobile what are the basic contraints we should keep in mind to have a GDPR complaint site and apps.

 

What should be the application architecture for web if we consider .NET MVC as technology stack and html css js as frontend. If we use API what would be the standards for API to use .

 

Thanks in advance.