FrontendHaltHTML·Intermediate·Conceptual·1 min read
What is the boundary between client and server validation?
Short interview answer
Client validation improves feedback and reduces avoidable requests, but it can be bypassed. The server validates authorization, integrity, and business rules and returns field or form errors that the client presents without losing user input.
Key takeaway
Explain the underlying mental model clearly, then support it with a concrete example and its trade-offs.