Requirements

Functional Requirements:

• Create a short URL for a given long URL.
• Return the long URL associated with a given short URL.

Non-Functional Requirements:

• It should be scalable to handle thousands of requests
• Fast retrieval
• high availability, since it has to be able to redirect thousands of users without fail

Capacity Estimation

Estimate the scale of the system. Consider daily active users, read/write ratio, storage requirements, bandwidth, and any relevant QPS calculations...

API Design

We implement two endpoints:

1. POST /shorten to receive a url and return the shortened version
2. POST /redirect which will redirect the user with short url to the actual one

High-Level Design

Our controller will catch the requests for these two flows:

1. when request hits /shorten, our service will generate a random 5 character unique string, save it to db and return it along with the domain(e.g shortener.com/jwB2a)
2. when request hits the /redirect, we will search for the actual link with the given one in the path and send a 308 redirect back to the user to the actual link

Database Design

Define the data model. Identify the main entities, their attributes, and relationships. Consider the choice of database type (SQL vs NoSQL) and justify your decision based on access patterns...

Detailed Component Design

our url generation service randomly generates a string 5 characters long, checks for it in the db, if it doesn't exist, it saves and returns it(if it doesn't it keeps generating new ones). our redirect service checks the cache first for the url and if it's not there, it will check the database and return the actual url.