System requirements

Functional:

A: Create short alias URL from original URL

B: reroute short alias URL to original URL

Non-Functional:

latency:

we need B requirement (reroute) to be at most 10 ms

A can be slower, maybe 1 second

scalability:

300,000 creates a day

1,500,000 reroutes a day

availability:

reads are the most important

consistency:

eventual consistency is good enough

Capacity estimation

4200 bytes * 300,000 per day = 1,240 mb

50 terabytes for 10 years

API design

createAlias(url: string, user_id: string (uuid), experation_time: string? = None)

• creates the alias, saves data to db

reroute(alias)

• fetches db data, reroutes

Database design

we will use a NoSQL because it's more performant, the data is not specifically

alias:

id: 8 byte string PK

URL: 2048 character string - up to 4096 bytes SK

created_at: 16 byte string

user_id: 16 byte uuid string

user:

id: 16 bytes uuid PK

created_at: uuid

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

client can

• create alias which will create the db data
• reroute which will call cdn

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?