System Design
Senior
system_design
Design a URL shortening service
You need to create a service that takes a long URL and returns a shortened identifier, typically a random string that can be mapped back to the original URL. Consider scalability, fault tolerance, and the possibility of collisions in your design. How would you structure the system? Which database(s) would you use and why?
Considerations:- How will you handle redirects?
- What happens when a user requests an already shortened URL?
- How would you go about scaling your service as it grows?
To design a URL shortening service, I would consider a microservices architecture. First, we would have an API that receives long URLs and generates short unique keys, potentially using a base62 encoding scheme for shorter string lengths. Services would include a key-value store like Redis for fast access and a relational database for persistent storage to manage the mappings between original and shortened URLs. We should implement caching for high-traffic URLs and set up redundant systems to ensure availability. Handling collisions might involve checking if the generated short URL already exists and generating a new one if so. Redirect handling can be done through a simple GET request to our service that translates the shortened key back to the original URL and performs the redirect.
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