System requirements

Functional:

URL shortener

URL fetcher (lengthener)

analytics (clicks) -> caching

Non-Functional:

1 to 1 mapping of long-short url

low response time to generate short url

scaling -> database and caching of URL, prob horizontal SQL DB

Capacity estimation

200 shortening/sec, 20k redirecting/sec

API design

Define what APIs are expected from the system...

url

string: long_url

string: short_url

int?: num_clicks

Database design

columns: id, long_url, short_url, num_clicks

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?