FrontendHaltJavaScript·Intermediate·Conceptual·1 min read
Why is mutating built-in prototypes risky?
Short interview answer
It changes behavior globally, can collide with future platform additions, affects unrelated code, and complicates enumeration and security assumptions. Use standalone utilities, composition, or carefully scoped polyfills that follow standards.
Key takeaway
Explain the underlying mental model clearly, then support it with a concrete example and its trade-offs.