System requirements

URL Shortening: take a long URL and generate a unique short URL back
URL Redirection: When a short URL is accessed, it should redirect to the original long URL.
Custom URL Option: Users may want to create a short URL with a specific alias (optional).
Analytics: The service might track how many times a short URL has been
Expiration: The ability to set an expiration date for short URLs (optional feature).
User Management: If the service requires user accounts, functionality for registration, login, and managing user URLs.
Error Handling: Provide user-friendly error messages for invalid URLs or when a short URL does not exist.

Performance: The service should be able to handle a significant number of requests per second. For example, you might aim for 1000+ requests per second without noticeable latency.
Scalability: The system should be designed to scale horizontally to accommodate increasing amounts of traffic and data.
Reliability: The service should be highly available, with minimal downtime. An uptime of 99.9% or higher is often targeted.
Security: Implement measures to prevent malicious links and protect user data. HTTPS should be enforced to protect the integrity of the URLs being accessed.
Maintainability: The architecture should be designed in a way that allows for easy updates and maintenance without significant impact on service availability.
Usability: The user interface should be intuitive, making it easy for users to shorten URLs and manage their links.
Data Consistency: Ensure data integrity and consistency, especially when users are creating short URLs and those URLs are stored in a database.
Cost-efficiency: The system should be designed to minimize operational costs while providing the required functionalities.