System requirements

Functional:

Generate short url when given a long url

Direct to the long url when given a short url

Non-Functional:

High abailability

Reliable

Scalable

Capacity estimation

About 100M users

API design

getShortUrl()

getLOngUrl()

Database design

Will use No_sql database, Cassandra

High-level design

User made a request to get a short URL, with the Long URL pass in, it comes to the shortUrl service, it will store them in the database

Request flows

Explain how the request flows from end to end in your high level design. Also you could draw a sequence diagram using the diagramming tool to enhance your explanation...

Detailed component design

Dig deeper into 2-3 components and explain in detail how they work. For example, how well does each component scale? Any relevant algorithm or data structure you like to use for a component? Also you could draw a diagram using the diagramming tool to enhance your design...

Trade offs/Tech choices

Explain any trade offs you have made and why you made certain tech choices...

Failure scenarios/bottlenecks

Try to discuss as many failure scenarios/bottlenecks as possible.

Future improvements

What are some future improvements you would make? How would you mitigate the failure scenario(s) you described above?