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:

• System shall have high availability as the shortened URL may be accessed in a variety of environments or scenarios
• System shall be reliable and performant, minimizing any additional latency added to the URL loading proces

API Design

1. (POST) /<url>/shorten
   1. Stores the newly shortened URL
   2. Request format - The client provides the long URL and some piece of information that can prove that they are the owner/host of the URL.
   3. Response format: 200 if successful, 403 if not authorized, 500 if invalid data
2. (GET) /<url>/info
   1. Allows the web host to retrieve their shortened URL as needed. Promotes availability for the host.
   2. Request Format: The long URL and authorization info.
   3. Response format: 200 if successful, 403 if not authorized, 500 if invalid data. Consistent with the POST payload requirements
3. (GET) /<url>/redirect
   1. Redirects the end-user to the shortened URL if available
   2. Request Format: The shortened URL.
   3. Response format: 200 Success and logic triggering the redirect occurs. 404 if error, 403 if unexpected headers are provided

High-Level Design

-User and Client feed through an API Gateway containing two base services: The shortening service and the Redirect service.

-The shortening service contains the business logic for creating the shortened URL as well as the mapping between actual and shortened URL.

-The redirect service is used when the end-user enters the shortened URL in their browser. It effectively redirects them to the correct web page using the shortened URL.

-The database is where the mapped URLs (long and short) are stored. If the service is to be implemented around the globe, a CDN or distributed architecture may be considered

Detailed Component Design

Deep dive into 2-3 key components. Explain how they work, how they scale, discuss tradeoffs, capacity, and any relevant algorithms or data structures.