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

Capacity Estimation

Estimate the scale of the system. Consider daily active users, read/write ratio, storage requirements, bandwidth, and any relevant QPS calculations...

API Design

We need two API endpoints.

POST /create

Takes a URL in the POST body and returns the unique ID associated with the URL.

GET /{id}

Returns the URL associated with the ID.

High-Level Design

When creating a short-URL, the server adds a row to a database column contains the ID and the URL. For low latency, we use a redis cache for retrieval requests to avoid excessive database requests.

Database Design

Let us keep it simple and have a table with 3 columns: id, shorturl_id, url.

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.