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:

• low latency
• high availability
• high consistency
• high durability
• scalable

API Design

PUT endpoint -> takes in long URL as an argument -> returns short URL.

GET endpoint -> takes in short URL as an argument -> returns long URL

High-Level Design

REST layer -> PUT(string longUrl) -> synchronous operation -> Business layer

Business layer -> Use 66 characters (a-z, A-Z, 0-9, -, _, ., ~) -> base 66 encoding

idea 1: use hash function to do base 66 encoding

pros: fast, deterministic

cons: collisions prone

idea 2: create a randomized string of 10 characters

pros: no collission. if collision detected, create another randomized string.

cons: extra logic

Data layer: Since system will be read intensive, choose database like SQL optimized for high reads.

will store long URL as key and short URL as value.

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.