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:

• High performance on reads
• High availability
• Low latency
• Horizontal scalability

API Design

POST /urls

Purpose

To create a shortened url

Inputs

url: String

Success response

201 created, when a record is successfuly created

{ url: "ourdomain.com/" }

Error responses

409 conflict, when a url already exists

400 bad request, when the provided url is not a valid url

500 internal server error

GET /

Purpose

To redirect a user to a real world url

Inputs

N/A

Success response

302 redirect, when a url matches the hash

Error responses

404 not found, when no url matches the hash

500 internal server error

High-Level Design

Describe the overall system architecture. Identify the main components needed to solve the problem end-to-end. Use the diagramming tool to create a block diagram.

We only need a simple Client, Server, and Database for this application.

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.

Rest API

The api will have a POST endpoint that receives a URL to be shortened from the client. That url will be hashed and stored in a key-value DB like DynamoDB for O(1) lookup with the key being the hash, and the value being the url. Once successfully created, the api will return the shorted url, "/" to the client so it can be copied. Our api will have middleware that catches non-post requests like GET "/", it will parse out the hash from the incoming request, and perform a redirect on successful lookups. Failed lookups will 404. Since this app is so simple, and yet may require extremely heavy loads, I'd write it in rust for performance. Simple horizontal scaling should work perfectly for performance needs.

Client

The client can be a simple react SPA. React allows for extensibility in the future of the project if we want to add accounts, auth, saved links, and more.