1. System Goals

The primary goals of a TinyURL system are:

1.1. URL Shortening

• Convert long URLs into short, unique identifiers.
• Ensure that the generated short URLs are easy to share and memorable.

1.2. URL Redirection

• When users visit a short URL, the system should quickly redirect them to the original URL.
• Ensure low latency for a smooth user experience.

1.3. Scalability

• The system should handle millions of requests per day.
• Support both read-heavy and write-heavy workloads efficiently.

1.4. Uniqueness & Collision Avoidance

• Ensure that every short URL is unique.
• Avoid collisions in the URL generation process.

1.5. High Availability & Reliability

• The service should have minimal downtime.
• Use distributed systems to handle traffic spikes.

1.6. Security & Abuse Prevention

• Prevent brute force attacks and unauthorized access.
• Block malicious URLs that lead to spam or phishing websites.

1.7. Optional Features

• Custom Short URLs: Users can specify their own short links.
• Expiration & Deletion: URLs may expire after a set time.
• Analytics: Track clicks, geographic data, and usage trends.
• API Support: Allow developers to integrate the URL shortener into their applications.

2. Functional Requirements

These define what the system should do.

2.1. Core Features

• Shorten URL – Convert long URLs into short ones.
• Redirect URL – Map short URLs to original URLs for redirection.
• Ensure Uniqueness – Generate unique short URLs for different long URLs.

2.2. User Features (Optional)

• Custom Short URLs – Allow users to choose their own short link.
• Link Expiry – Users can set an expiration time for the URL.
• Analytics – Track usage metrics for each shortened URL.
• Delete URLs – Users can delete their shortened URLs if needed.
• API Access – Provide an API for programmatic URL shortening.

3. Non-Functional Requirements

These define system constraints and performance expectations.

3.1. Performance & Speed

• URL redirection should happen in less than 100ms.
• Caching mechanisms (like Redis) should be used to speed up lookups.

3.2. Scalability

• The system should handle high traffic efficiently.
• Load balancing and replication should be used to distribute the load.

3.3. Reliability & Fault Tolerance

• Data should be stored in a replicated distributed database to prevent data loss.
• The system should be resilient to failures and support failover mechanisms.

3.4. Security

• Prevent brute-force attacks on short URLs.
• Implement rate limiting to prevent abuse.
• Scan and block malicious URLs that lead to phishing sites.

3.5. Storage Efficiency

• Use a compact encoding scheme (Base62) to store short URLs efficiently.
• Delete expired or unused URLs to free up space.