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Design a Moderated Messaging Service
Design a Moderated Messaging Service
Design a one-to-one messaging system with the following requirements:
- A user can send a message to another user.
- Users can view their chat history.
- Every outgoing message must be checked by an external AI moderation service for inappropriate text.
Discuss the end-to-end architecture, data model, APIs, and storage choices. Then address these follow-up questions:
- If a large burst of messages arrives, how would you prevent the system from crashing or running out of memory?
- The external AI service can be slow. How would you keep the user experience responsive while still preventing unsafe content from reaching recipients?
- How would you handle retries, failures, and duplicate processing?
AI interview prep
Core dilemma
Balancing real-time user experience and message delivery with the latency and potential unreliability of an external AI moderation service, while ensuring data integrity and system resilience under load.
Mid-level signals3
Senior signals3
Red flags3
3 tradeoffs and 2 stress tests locked
Interview prep
Unlock the interviewer X-Ray rubric, tradeoff matrix, stress tests, clarifying questions, and key concepts.
Design a Moderated Messaging Service
Design a Moderated Messaging Service
Design a one-to-one messaging system with the following requirements:
- A user can send a message to another user.
- Users can view their chat history.
- Every outgoing message must be checked by an external AI moderation service for inappropriate text.
Discuss the end-to-end architecture, data model, APIs, and storage choices. Then address these follow-up questions:
- If a large burst of messages arrives, how would you prevent the system from crashing or running out of memory?
- The external AI service can be slow. How would you keep the user experience responsive while still preventing unsafe content from reaching recipients?
- How would you handle retries, failures, and duplicate processing?