System requirements
Functional:
- URL Shortening: Users should be able to input a long URL and receive a shortened alias.
- Redirection: When users access the shortened URL, they should be redirected to the original long URL.
- Custom Alias: Users should have the option to customize the shortened alias for their URLs.
- Link Expiration: Ability to set expiration dates for shortened links.
- Analytics: Tracking and providing analytics on the usage of shortened URLs.
- Link Management: Users should be able to manage and edit their shortened URLs.
- API for Integration: Providing an API for developers to integrate URL shortening functionality into their applications.
- Security: Ensuring secure and reliable shortening and redirection of URLs.
- Scalability: Ability to handle a large number of requests efficiently.
Non-Functional:
- Performance: The system should provide fast response times for both shortening and redirection processes. It should be able to handle high traffic efficiently.
- Scalability: The system should be able to scale horizontally to handle an increasing number of shortened URLs and user requests.
- Availability: The URL shortening service should have high availability to ensure users can always access their shortened URLs.
- Reliability: The system should be reliable, ensuring that shortened URLs always redirect users to the correct long URLs.
- Security: Implementing measures to secure both the shortening process and the stored URLs to prevent misuse or unauthorized access.
- Monitoring and Logging: Logging activities, monitoring performance, and tracking system behavior for troubleshooting and optimization.
- Backup and Recovery: Implementing backup mechanisms to prevent data loss and enable recovery in case of failures.
- Compliance: Ensuring compliance with data protection regulations and privacy policies in handling user data.
Capacity estimation
Estimate the scale of the system you are going to design...
- Daily Traffic: Let's estimate that the service will receive 1 million URL shortening requests per day.
- Redirection Rate: Assuming each shortened URL will be accessed 10 times on average, resulting in 10 million redirection requests per day.
- Peak Traffic: Planning for peak times where traffic could increase by 2-3 times the daily average.
- URL Storage: Approximating that each URL entry may require around 100 bytes of storage in the database.
- Analytics Data: Storing analytics data for each shortened URL visit (e.g., timestamp, IP address) could add additional storage requirements.
API design
Define what APIs are expected from the system...
Database design
Defining the system data model early on will clarify how data will flow among different components of the system. Also you could draw an ER diagram using the diagramming tool to enhance your design...
High-level design
You should identify enough components that are needed to solve the actual problem from end to end. Also remember to draw a block diagram using the diagramming tool to augment your design...
Request flows
Explain how the request flows from end to end in your high level design. Also you could draw a sequence diagram using the diagramming tool to enhance your explanation...
Detailed component design
Dig deeper into 2-3 components and explain in detail how they work. For example, how well does each component scale? Any relevant algorithm or data structure you like to use for a component? Also you could draw a diagram using the diagramming tool to enhance your design...
Trade offs/Tech choices
Explain any trade offs you have made and why you made certain tech choices...
Failure scenarios/bottlenecks
Try to discuss as many failure scenarios/bottlenecks as possible.
Future improvements
What are some future improvements you would make? How would you mitigate the failure scenario(s) you described above?