Can someone please provide me source(video,notes,link) for the 3 following design questions.

1. Design internationalization
   not able to find answer like How to add Dynamic data into string . , How to map to string .
   no idea about this design question . can someone please tell me what to explain in this

2. Business facing API for product listing ADS
   not able to find any information on internet for Dynamic Products Ads Design Question, Can someone share a thought , how to explain this in interview , where to start and what should be functional requirement .
   if any blog or any video , please share
   3)Design Metric Collection System
   how to explain this in interview , where to start and what should be functional requirement .
   if any blog or any video , please share

Generally i am watching video on youtube , How to design Twitter, Netflix ,Uber .. but what to do in this kind of questions?
Please help , need suggestion .