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, scalability, reliability, correct redirection

API Design

GET /redirect/{Randomstring}

POST /createmapping

PUT /updatemapping

DELETE /mapping/{id}

GET /mappingDetails/id

High-Level Design

From the browser we call a service redirect/randomstring

we basically return a permanent redirect response

we first check if the mapping exists if yes we check if its present in cache else fetch from db and return

and all of this can be behind a load balancer

Detailed Component Design

From the browser we call a service redirect/randomstring

we basically return a permanent redirect response

when we get the Given url to shorten we basically can check if this was shortened previously using a bloom filter

if not we can go ahed with creation of new mapping

in case it exits we return the existing one either from cache or DB

we can have a cache key with TTL of 10 min and LRU policy

and we can use redis for this

as this would be a high throughput service we can use Scylla or Cassandra

and all of this can be behind a load balancer