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Meta·Technical Product Manager·Onsite - System Design / Architecture·Senior

Senior
Apr 2026

Summary

Meta TPM interview with a system design question around fake news detection. Pretty open-ended, which I wasn't fully prepared for.

Questions Asked (1)

Q1

How would you design a fake news detection system?

System DesignProduct StrategyTechnical Trade-offs
Author's notes

I started with the data pipeline and content ingestion layer, which felt right, but then I got lost trying to define what 'fake' actually means at scale.

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AI HintsAI Generated

Suggested Approach

Start by clarifying the goal: to reduce the spread of misinformation while balancing false positives and user experience. Then outline a multi-layered system that combines machine learning models, human review, and product interventions like labeling and downranking. Emphasize trade-offs between accuracy, scalability, and user trust, and propose metrics to evaluate success.

Pro tip: Acknowledge that fake news detection is an adversarial problem where bad actors constantly evolve, so the system must be adaptive and include feedback loops. Also, highlight the importance of transparency and user education to maintain trust.

1. Define Objectives and Scope

Clarify what constitutes 'fake news' (misinformation, disinformation, clickbait) and set goals like reducing spread, increasing accuracy, and maintaining user trust. Consider the platform's policies and ethical implications.

2. Design Detection Pipeline

Propose a multi-stage approach: content-based signals (NLP, source credibility), behavioral signals (sharing patterns), and network analysis. Combine automated models with human fact-checkers for edge cases.

3. Define Interventions

Decide on actions: labeling, downranking, warning screens, or removal. Balance effectiveness with potential backlash and ensure interventions are explainable.

4. Address Trade-offs and Metrics

Discuss trade-offs: precision vs. recall, speed vs. accuracy, automation vs. human review. Define success metrics: reduction in spread, user reports, precision/recall, and user trust surveys.

5. Plan for Iteration and Scalability

Outline how the system will learn from new data, adapt to adversarial tactics, and scale globally. Include A/B testing, feedback loops, and cross-functional collaboration.

Key Points to Mention

  • Multi-modal detection: text, images, video, and metadata
  • Use of pre-trained language models (e.g., BERT) and graph neural networks for propagation patterns
  • Human-in-the-loop for ambiguous cases and model improvement
  • Product interventions: labeling, downranking, and providing context
  • Metrics: precision, recall, false positive rate, user engagement, and trust
  • Adversarial nature: need for continuous monitoring and adaptation

AI-generated suggestions, not part of the candidate's original notes. May be inaccurate — verify before relying on them.