System requirements

Functional:

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

Same URL can have the same tiny url

different tiny urls should point to different urls

users can delete tiny urls

users cannot update tiny urls

Non-Functional:

List non-functional requirements for the system...

high availability

low latency

authentication and authroization will not be considerred

Capacity estimation

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

10000 tps for url creation

100 tps for url deletion

API design

Define what APIs are expected from the system...

createTinyUrl

deleteTinyUrl

getOriginalUrl

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...

table with tinyUrlId and originalUrl

Primary Key is tinyUrlId and with indexes created on the originalUrl

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...

create tiny url:

• User post origin url
• Query database to see if there's a tiny url point to the origin url
• if not, generate an uuid and test if the uuid is usable (query the database to see if there's an record with the uuid) this process can have retries to ensure uuid is unique
• write both uuid and url to the database

users -> delete tiny urls

• User post tiny url id
• Remove the given record from the database

visit url

• User visit the tiny url
• Search for the origin url
• If found, redirect users to the origin url
• If not, return not found

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...

Url Generaton

Using UUID could simplify the implementation. UUID with retries should be good enough to handle the tps requirement.

Can have cache to store the tiny url mapping. However, need to be careful with the cache validation.

The main components will be a load balancer in front of a group of servers, those servers will connect to the redis cache for read purpose and database for write purpose. The cache will be updated upong tiny url creation or tiny url deletion.

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?