System requirements

Functional:

• account management
• url shortening
• url management
• url redirecting
• url visitors count

Non-Functional:

• fast
• secure
• the url should be actully dhortened

Capacity estimation

totlal users : 1M +

15k users per day

15k hyperlinks generated per day

API design

• api/v1/users -> account management

this includes GET, POST, PUT and DELETE methods. I will leave the detail here since this is more common task

• POST: api/v1/shorten

Autorization JWT Token

body : longurl

returns the generated url

• GET api/v1/my-urls -> Get Users URLs
• api/v1/url/:id -> CRUD operation on specific url

needs autorization

• redirect/:shortened -> redirectes to the original url

it looks up to the actual url from db useinf :shortened as a key

Database design

User:

• userid : bigint
• email
• password
• fname
• lname

URL:

• urlid: bigint
• original-url
• shortened-url
• userid
• visiors-count

URLVisit:

• id : bigint
• userid
• urlid

Request flows

• Shortening

1. user sends url shorten request
2. The backend Generates a new url and saves to the database
3. the new url is returned to the user

• redirecting

1. a user clicks on the generated link
2. the backend looks up the actual url
3. the backend redirects the user to the actual url

Detailed component design

15k urls would be generated per day and there will be more than 5M urls generated.

all generated urls should be unique

• idea use user id to generate the url but for security and privacy reason the user generating the url shoulnt be known from the url alone
• suggestion : Generate primitive mongos primitive object id for each url this minimizes url conflicts guarantees uniqueness and fixes privacy issue
• use mongo db for database since the system is not transaction heavy

Trade offs/Tech choices

Failure scenarios/bottlenecks

multiple users may try to generate url at same time creating similar url for diferent redirects

Future improvements