System requirements

Functional:

1) Takes in URL string

2) Generates new URL that maps to original URL

3) Redirects from short URL to original URL

4) Unique generate URL

Non-Functional:

1) Performance: low response time

2) Available: 99.9% uptime

3) Reliable: 99.99% success rate

4) Scalable: handle traffic spikes

5) Security: rate limiting

Capacity estimation

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

let's assume 100000 requests per day

80000 read requests

20000 write requests

API design

shortenURL(str originalURL, str userID, datetime expiration_date)

redirectURL(str URL)

Database design

key-value db

we will use shortenedURL as a primary key to enforce uniqueness

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?