System Design Interview Questions by Level: Junior, Mid-Level, Senior, and Staff
Not every system design interview evaluates the same thing.
A junior engineer may be asked to design a URL shortener and explain why a cache would help. A mid-level engineer could receive the same question but be expected to estimate traffic, choose a database, and handle key collisions.
A senior engineer may need to discuss multi-region deployment, consistency, failure recovery, and operational trade-offs. A staff engineer could be pushed further into migration strategy, organizational boundaries, cost, and the long-term evolution of the platform.
The question may look identical. The expected answer is not.
