System requirements

Functional:

List functional requirements for the system (Ask the chat bot for hints if stuck.)...

• user should be able to provide a long url and get a short version back.
• the short url should be remembered (discuss for how long or maybe by usage)
• each user can create multiple tinyurls
• user profile for managing creations?

Non-Functional:

List non-functional requirements for the system...

be able to take high traffic

redirect should happen in less than 300ms of getting the request

handle 1M+ DAU

availability > consistency

more read heavy than write heavy

Capacity estimation

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

DB:

each large url avg: 150 characters

1 char = 1 byte * 150 = 150bytes * 1B Urls =

1,000,000,000 * 150 = 150B bytes (~)= 1.5G

each small url = 15 chars = 150MB

bit.ly/123456

(~)= 2GB for 1B

user profile: 1MB

100M users * 1MB = 1,000,000 * 1 = 100M mb = 1000GB = 1TB

API design

Define what APIs are expected from the system...

GET url: /api/url/ which will cause redirect in browser

POST: /api/url new url mapping

DELETE: /api/url delete a mapping

Database design

Defining the system data model early on will clarify how data will flow among different components of the system. Also you could draw an ER diagram using the diagramming tool to enhance your design...

use SQL db

user

name

email

hashpass

userid

urls

id

userid

url

tinyurl

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?