Requirements

Functional Requirements:

• Create a short URL for a given long URL.
• Return the long URL associated with a given short URL.
• User can create short URL with their own defined alias
• URL will expire after certain time

Non-Functional Requirements:

• Redirect with low latency
• High availablity

API Design

Define the APIs expected from the system. This is your chance to analyze and define the read and write paths so that you can come up with the high-level design...

POST /v1/create -> shortURL

{

longURL

alias?

}

GET /v1/{shortURL}

return 301 or 302 HTTP status (redirect)

High-Level Design

Create short URL:

• Hashing or if alias is provided, we create based on alias

Get:

• Cache to store shortURL-> longURL mapping, if cache is missed, fetch from DB
• Check shortURL as index and return the corresponding long URL

Cache:

• before DB, if hit cache, return to reduce latency

DB:

• SQL database, two tables

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.