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: Redirect latency < 100ms
• Resiliency
• High availability
• Horizontal scalability
• Caching for frequently accessed URL

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...

High-Level Design

Client hits the CDN which directs them to our server Load Balancer. This Load Balancer will distribute the workload on a round robin basis to one of multiple servers. These servers will take the shortened URL and look first to Redis to see if the URL is cached. If there is a cache miss, we will look into a database to find the long URL. This long URL will then be returned to the client.

Detailed Component Design

The Load Balancer will use a Round Robin approach to distribute workloads.

Redis will use a LRU policy to evict old URLs, and a TTL of a week.