Requirements

Latency - The URL should be created within 100ms and same goes for the redirection of the URL when the short URL is called.
Consistency - The system should be highly consistent, we cannot tolerate wrong redirection
Availablitlty - The system should be available all the time, for better user experience
1 billion daily users, 10% active users so 100 million each creartinf 5 requests a day - so 500M requests a day
from this consider 20% are for creating up the URL and 80% accessing the correct full path based on the provided short URL