System requirements

Functional:

• Shorten a URL
• Redirect a short URL to the original URL
• Support custom URLs
• Delete a short URL
• Manage my urls in a dashboard

Non-Functional:

• The availability is very important, we want the user to be forwarded to the original url all the time, the service should have little or no down time.

Capacity estimation

• Handle 1 million active users per day
• The system is read-heavy, so about 100K new urls per day, and 10 million redirects daily.

API design

• shorten_url(user, original_url, custom_url=null)
• find_original_url(user, shortened_url)
• delete_url(user, short_url)

Database design

• user (id, first_name, username, email, password, created_at)
• url (original_url, shortened_url, created_at, expiration_date, foreign_key=user_id)

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...

I will create a User component that is in charge of the registration and user dashboard, to show all of the URLs related to the User.

Another component for Shortening URLs, this component is simply in charge of receiving a user and the original url, and creating the corresponding short url in the database. This component is simply scalable, it's only dependency is url database.

I'll have another component for redirect, this component is very important since the system is read-heavy. I can use some redis cache for this component to cache the most popular URLs to avoid querying the database each time.

Request flows

The user requests to shorten a URL. The load balancer forwards the request to one of the Shortening URL components.

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?