Design content moderation for a posting app

## Scenario You are given a small demo “post creation” web app similar to a social network composer: - **Frontend:** a page where users type a post and submit. - **Backend:** Node.js service. Many features are currently **mocked/stubbed**. You must add a **policy-violating content detection** module. ## Requirements 1. **Detect potentially violating content** in user-submitted posts (text is sufficient; you may mention how you’d extend to images/links). 2. Provide a **user experience** during composition/submission: - Show a **warning/prompt** when content is suspected to violate policy. - Optionally **mask** violating spans (e.g., replace characters with `*`). 3. The solution should be **extensible** (easy to add new categories/rules/models) and safe to evolve. 4. Discuss and/or implement (high-level is fine): - API contracts between frontend and backend - data model or response schema (e.g., violations, spans, severity, suggested edits) - latency and failure behavior (what happens if detection is slow/unavailable?) - logging/metrics for monitoring quality and abuse ## Interview follow-up After you present your approach, expect two additional feature requests (e.g., add a new violation type, add an override/appeal flow, add an admin configuration toggle) and explain how your design supports implementing them quickly.