FrontendHaltSecurity·Intermediate·Conceptual·1 min read
How would you review a feature that renders user-authored rich text?
Short interview answer
Define the allowed formatting model, sanitize on a trusted boundary with a maintained allowlist, sanitize or encode again for the actual sink as appropriate, restrict URLs and embeds, deploy CSP, test mutation and parser edge cases, and avoid allowing arbitrary style or script-capable markup.
Key takeaway
Explain the underlying mental model clearly, then support it with a concrete example and its trade-offs.