System requirements

Functional:

• Take from the user the Long Url
• Create short URL and store the long URL and its short in the database and return it to user
• Redirect the user to the original URL when the user click on this short Url or access it

Non-Functional:

• Performance
• reliability and availability
• scallablity

Capacity estimation

• Users ---> 10M
• Daily Active User ---> 1M
• Avarage Requests for user per day ---> 2 Request/day
• 200KB for each shortage process

Estimation :

• 2 * 1 = 2M Request per day
• data -> 2M * 200KB = 390.625 GB

API design

• Shortage Endpint

-Method -> Post

-URL --> /api/short/:url

-Params --> url

• Redirect Url

-Method --> Get

-Url -> /api/redirect/:url

-Params -> url

Database design

• Entities: --> ShorageUrl
• attraibutes

ShortageUrl -> id : string, long_url: string , short_url: string, CreateedAt: Date

• Pri,arry Key--> Id

High-level design

the main components in this system are :

• Frontend
• Backend
• Database
• Caching
• Loadbalancer

the main modules

• Shortage Module
• Redirect

Request flows

The First Request is to create the Short URL :

the client send the long URL to server and server process it and store the long and short URL and store them in he database

the second one is to redirect the user to the original URL :

the clcint already has has the short URL and he click on it so access the server to redirect the user to the origin al URL based on the shortage URL

and this system ahas cahning feature to fast the redirect process for the user and also has the loadbalaincer to distribute the requests for many nodes or pods or servers to increase the performance

Detailed component design

this ystem ahs tow components or modules one for creating and another for the redirect the user

The first One for Create the shortge Url :

the user send to server the long URL the server use alogright to create short URL and this URL not replication for any user and store them in the database e and return it to user

the second one for redirect the user to the original Ulr

the user access the endpoint and send to server the short URL as a params the module take to this URL chack if exist or not if yse redirect the user to origin al URL if not return the user not found result

Trade offs/Tech choices

Frontend : ReactJs --> Trad of -> make the SEO week

Backend : NestJs --> Trad offs --> diffult to learn

Database : PostgreSQL

Caching : Rddis

Load balaincer: NGINX

Hosting: AWS or Hostinger

Failure scenarios/bottlenecks

• May the two or more url ahs the same shorteg url
• database dwon or server down
• cashing fail

Future improvements

• add the authintication system
• add user management his url and his profile
• add lin or URL management to enable the user to view who click on this profile and so on