FrontendHaltHTML·Intermediate·Conceptual·1 min read
How do you prevent duplicate submission?
Short interview answer
Treat submission as a state transition, make the server operation idempotent where necessary, prevent repeated client activation while pending, and recover cleanly from timeout or failure. Disabling alone is not a server-side guarantee.
Key takeaway
Explain the underlying mental model clearly, then support it with a concrete example and its trade-offs.