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:

List the key non-functional requirements (eg low latency, scalability, reliability, etc.)...

API Design

POST/ shorten

Request: { longUrl }

Response: { shortUrl }

GET/{shortId}

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.

Detailed Component Design

stateless API server

Responsibilites

=> Handle incoming requests for URL shortening and redirection

=>communicate with cache, database, and id generator

=>ensure statelessness to support horizontal scaling

Why stateless?

easy horizontal scaling

fault tolerance

ID generator

Purpose

Generate unique short IDs for URLs in a distributed environment

Design choice

=> use snowflake style ID generation or atomic counter + Base62 encoding

Working

=> API server requests a new ID

=> ID generator returns a globally unique numeric ID

=> ID is encoded using Base62 to generate short URL

Benefits

=> prevents ID collisions

=> avoid database auto- increment bottleneck

=> supports high write throughput

Cache and Database layer

cache(Redis)

=> stores short URL -> long URL mapping

=> Read through cache strategy

=> TTL- based expiration with LRU eviction

=> Reduce database load and improve read latency

Database(Nosql)

=> persistent key value storage for URL mappings

=> schema: short_url_id -> long_url

=> Horizontally scalable via sharding

=> Replicated for high availability

Failure Handling

Cache miss -> fallback to database

cache failure-> direct database access