System requirements

Functional:

1. the system should provide the original URL based on the given shorted URL
2. system allows authorized people to create new shorted URLs for their service
3. Systems allows permanent delete of shorted URLs mapping for authorized users
4. Have a restful API for the requests

Need to provide the shorted URLs to clients. The URLs should have 1：1 mapping relationship. Thus the produced unique shorted URL should be saved in database. The database should be Once-write type. Not allowed change to the generated value.

To ensure the efficiency , there should be two database. One is write only and another one is read only. The readonly database will sync with the write only database in short gap.

Cache also need to be introduced to reduce the frequency of lookup

Non-Functional:

List non-functional requirements for the system...

Capacity estimation

Estimate the scale of the system you are going to design...

API design

We expect Get , put and delete from the Restful API

Get will return the content of original URLs

PUT nwill create new mapping of the shortened URLs and original URLS

DELETE will remove the mapping in the database forever

PUT and DELETE will require the User authentication

Database design

I will require to have 3 databases, one database to store the mappings which only allows write and delete not editing allowed

one database that will sync from the write only database and it should have high reading speed

Above two needs mappings data structures

one database used for user authentication checking. This database will not require to have high read/write capability

High-level design

You should identify enough components that are needed to solve the actual problem from end to end. Also remember to draw a block diagram using the diagramming tool to augment your design. If you are unfamiliar with the tool, you can simply describe your design to the chat bot and ask it to generate a starter diagram for you to modify...

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?