Your question is URL Shortener Design. Take a moment with it on the right.
Talk me through your thinking if you like. When you're confident, submit your answer and I'll grade it like a real screen (7/10 or better passes).
Design a URL shortener system (LLD + HLD).
Discuss the core classes and APIs, short-code generation, persistence, redirect handling, caching, expiration, collision prevention, and analytics. Clarify assumptions such as expected traffic, availability, custom aliases, abuse controls, and read/write latency before presenting the design.