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Meta·Data Scientist·Onsite - Product Sense / Strategy·Senior

SeniorPrefer not to say
Jun 2026

Summary

Integrity-focused DS case at Meta, all about designing a severity metric suite for harmful content. Heavy on measurement theory and tradeoffs, less coding. Walked out feeling like I'd spent an hour arguing with myself about what 'harm' even means.

Questions Asked (8)

Q1

Design a metric or metric suite to measure the severity of harmful/policy-violating content on a large social platform. You have impression logs, content metadata, partial human-review labels, and ML classifier scores. What do you propose?

Product Analytics & MetricsSystem DesignTechnical Trade-offs
Author's notes

This is the kind of question where jumping straight to a single ratio gets you killed.

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AI HintsAI Generated

Suggested Approach

Start by clarifying the goal: measuring severity of harmful content exposure on the platform, not just prevalence. Propose a metric suite that combines prevalence, exposure-weighted severity, and user impact, using impression logs, content metadata, human labels, and ML scores. Discuss how to calibrate and validate the metrics, and address trade-offs like false positives/negatives and gaming.

Pro tip: Emphasize that severity is not just a property of content but also of exposure and user context; propose a tiered severity framework and show how to estimate platform-level severity using a combination of labeled data and model scores with uncertainty quantification.

1. Define severity and scope

Clarify what 'severity' means: harm level per piece of content, and how to aggregate to platform level. Consider dimensions like type of harm, user vulnerability, and exposure.

2. Leverage available data

Use human labels to define a severity scale, ML scores to predict severity for unlabeled content, and impression logs to weight by exposure. Incorporate content metadata for context.

3. Design metric suite

Propose metrics: (a) Prevalence of severe content in impressions, (b) Exposure-weighted severity score, (c) User-reported harm rate, (d) Model-estimated severity distribution. Combine into a composite index if needed.

4. Validate and calibrate

Use human labels to calibrate ML scores and estimate false positive/negative rates. Validate metrics via A/B tests or holdout sets. Quantify uncertainty.

5. Address trade-offs and operationalization

Discuss trade-offs: precision vs recall, timeliness vs accuracy, gaming risks. Suggest how to monitor and update metrics over time.

Key Points to Mention

  • Severity is multi-dimensional: consider harm type, user vulnerability, and context.
  • Use impression logs to weight by exposure, not just content prevalence.
  • Combine human labels and ML scores via calibration (e.g., Platt scaling) to estimate severity on unlabeled data.
  • Propose a tiered severity scale (e.g., 1-5) and map to policy violations.
  • Account for uncertainty: confidence intervals for platform-level metrics.
  • Discuss potential biases in human labels and ML models, and mitigation strategies.

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

Q2

The team wants to use View Prevalence (views of violating content divided by all views) as the primary KPI. What are the pros and cons?

Product Analytics & MetricsA/B Testing & ExperimentationTechnical Trade-offs
Author's notes

I liked this question because VP is genuinely seductive and genuinely broken in interesting ways.

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AI HintsAI Generated

Suggested Approach

Start by defining View Prevalence and its role as a KPI, then systematically discuss its pros (e.g., direct measure of harm, easy to interpret) and cons (e.g., susceptible to gaming, may not capture severity). Finally, recommend complementary metrics and guardrails to ensure a balanced evaluation.

Pro tip: Acknowledge that while View Prevalence is intuitive, it can be gamed by reducing overall views; propose pairing it with absolute violation counts or severity-weighted metrics to prevent perverse incentives.

1. Define the Metric

Clearly define View Prevalence: the number of views of violating content divided by total views. Clarify what counts as 'violating content' and how views are measured.

2. Identify Pros

List advantages: directly measures user exposure to harm, normalizes for platform growth, easy to communicate, and aligns with integrity goals.

3. Identify Cons

Discuss drawbacks: can be gamed by reducing total views, doesn't account for severity or type of violation, may be noisy for rare events, and could incentivize over-removal of borderline content.

4. Consider Trade-offs and Alternatives

Compare with other metrics like absolute violation views, prevalence per user, or severity-weighted prevalence. Suggest complementary metrics to mitigate cons.

5. Recommend a Balanced Approach

Propose using View Prevalence as a primary KPI but with guardrails (e.g., total views, user reports) and regular audits to prevent unintended consequences.

Key Points to Mention

  • Definition and calculation of View Prevalence
  • Alignment with company goals (e.g., reducing harm)
  • Susceptibility to gaming (e.g., reducing overall views)
  • Lack of severity weighting (all violations treated equally)
  • Potential for over-removal of borderline content
  • Need for complementary metrics (e.g., absolute counts, user reports)

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

Q3

Walk through the key tradeoffs in choosing and optimizing these metrics. Cover at least: user safety vs. engagement, precision vs. recall, reporting robustness vs. sensitivity to change, and fairness across regions and languages.

Technical Trade-offsProduct Analytics & MetricsCross-functional Alignment
Author's notes

The precision-recall tension is the one I felt most comfortable with.

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AI HintsAI Generated

Suggested Approach

Start by framing metrics as tools for decision-making, then systematically address each tradeoff by defining the opposing goals, explaining when to prioritize one over the other, and giving concrete examples from Meta's products. Emphasize that tradeoffs are resolved through experimentation and cross-functional alignment, not purely technical optimization.

Pro tip: Anchor your answer in Meta's 'move fast' culture by highlighting how you'd use rapid A/B tests and guardrail metrics to dynamically balance tradeoffs, rather than seeking a perfect static solution. Show you understand that metrics are proxies for user value and business goals, and that tradeoffs shift with product maturity and market context.

1. Clarify the decision context

Ask clarifying questions about the product, stage, and stakeholders to understand which tradeoffs matter most. For example, a new feature might prioritize engagement, while a mature one focuses on safety.

2. Define the opposing metrics and their implications

For each tradeoff, clearly state the two sides (e.g., user safety vs. engagement) and explain what optimizing one at the expense of the other means for users and the business.

3. Propose a balanced approach with guardrails

Suggest using primary and guardrail metrics, and describe how to set thresholds or constraints to prevent unacceptable degradation on either side.

4. Leverage experimentation and iteration

Explain how A/B testing, multi-armed bandits, or causal inference can quantify tradeoffs and inform dynamic adjustments over time.

5. Address fairness and robustness across regions and languages

Discuss techniques like stratified analysis, fairness constraints, and robust metric design to ensure metrics work equitably across diverse populations.

Key Points to Mention

  • User safety vs. engagement: Use guardrail metrics (e.g., reports, blocks) to cap engagement optimizations; consider long-term vs. short-term engagement.
  • Precision vs. recall: Choose based on cost of false positives vs. false negatives (e.g., content moderation vs. friend suggestions); use F-beta scores or PR curves.
  • Reporting robustness vs. sensitivity: Balance stability (e.g., smoothing, minimum sample sizes) with ability to detect meaningful changes; use sequential testing or CUPED.
  • Fairness across regions and languages: Ensure metrics are not biased by data sparsity or cultural differences; use per-region/language analysis and fairness-aware optimization.
  • Cross-functional alignment: Involve product, policy, legal, and engineering to agree on tradeoff priorities and metric definitions.
  • Meta-specific examples: Reference News Feed integrity, Instagram well-being, or WhatsApp spam detection to ground the discussion.

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

Q4

Recommend a final metric suite. Which metric is the primary KPI, what are your diagnostic metrics, and what are your guardrails?

Product Analytics & MetricsProduct StrategyStakeholder Management
Author's notes

I went with severity-weighted view prevalence as the primary, basically VP but with each violation weighted by harm tier.

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AI HintsAI Generated

Suggested Approach

Start by clarifying the product context and business objective, then propose a metric suite with a primary KPI tied to the goal, diagnostic metrics to explain changes, and guardrails to prevent harm. Emphasize how these metrics will drive decisions and align stakeholders.

Pro tip: Tie each metric to a specific decision or action it informs, and explicitly state trade-offs between metrics to show strategic thinking. Mention how you would validate the suite with a holdout or A/B test.

1. Clarify Objective and Context

Ask clarifying questions to understand the product, user base, and business goal (e.g., growth, engagement, monetization). Confirm the stage (launch, mature) and constraints.

2. Define Primary KPI

Propose a single primary KPI that directly measures success toward the objective. Justify why it's the best proxy and how it aligns with company goals.

3. Select Diagnostic Metrics

Choose 2-4 diagnostic metrics that break down the primary KPI into actionable components (e.g., funnel steps, engagement depth). Explain how they help diagnose changes.

4. Identify Guardrail Metrics

List 2-3 guardrail metrics to monitor unintended consequences (e.g., user satisfaction, latency, revenue). Set thresholds for acceptable trade-offs.

5. Summarize and Validate

Recap the suite, explain how metrics interact, and propose a validation plan (e.g., A/B test, holdout). Discuss how you'd communicate results to stakeholders.

Key Points to Mention

  • Alignment with business objectives and company mission
  • Leading vs. lagging indicators and their roles
  • Funnel analysis and segmentation for diagnostics
  • Guardrails to prevent negative side effects (e.g., user churn, technical debt)
  • Trade-offs between metrics and how to prioritize
  • Statistical rigor: sample size, significance, and long-term impact

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

Q5

A new classifier improves recall by 15% in Spanish and Portuguese, and your severity-weighted metric rises as a result. How do you explain to leadership whether the platform actually got worse or your measurement improved?

Product Analytics & MetricsRoot Cause AnalysisStakeholder Management
Author's notes

This one caught me a little flat-footed.

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AI HintsAI Generated

Suggested Approach

Start by clarifying that a metric increase does not automatically mean the platform got worse; it could reflect improved measurement or a real change in model behavior. Then, systematically decompose the metric change into its components—model performance, data distribution, and metric definition—to determine the root cause. Finally, communicate findings to leadership with a clear, data-driven narrative that separates measurement improvements from actual platform changes.

Pro tip: Always validate metric changes with a holdout set and compare against a stable baseline to rule out measurement artifacts. When presenting to leadership, lead with the 'so what'—whether the change is real and actionable—and avoid jargon.

1. Clarify the metric and its components

Understand exactly how the severity-weighted metric is calculated and which components (e.g., recall, precision, severity weights) changed. This helps identify whether the increase is driven by measurement or model behavior.

2. Check for measurement improvements

Investigate if there were changes in data collection, labeling, or metric computation that could artificially inflate the metric. For example, improved recall in Spanish and Portuguese might be due to better language-specific data or model tuning.

3. Assess actual model performance

Evaluate the model on a consistent, unbiased holdout set to see if the improvement is real and generalizes. Compare against a baseline model to isolate the effect of the new classifier.

4. Analyze trade-offs and segment impacts

Check if the recall improvement in Spanish and Portuguese came at the cost of precision or performance in other languages. Determine if the severity-weighted metric increase is due to better handling of high-severity cases or just more false positives.

5. Communicate findings to leadership

Present a clear narrative: whether the platform improved, stayed the same, or worsened, and why. Use visualizations and simple language to explain the difference between measurement and actual performance.

Key Points to Mention

  • Distinguish between measurement changes (e.g., better data, metric definition) and actual model performance changes.
  • Use a holdout set and baseline comparison to validate the metric increase.
  • Consider segment-level impacts: recall improvement in Spanish/Portuguese might not generalize to other languages.
  • Check for trade-offs: increased recall could lead to more false positives, affecting precision and user experience.
  • Ensure the severity-weighted metric aligns with business goals and reflects true severity, not just volume.
  • Communicate with a clear, non-technical narrative focusing on actionable insights for leadership.

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

Q6

Would you use the weekly primary KPI to trigger on-call alerts for harm spikes, or would you design a separate alerting signal? What would that signal look like?

Product Analytics & MetricsSystem DesignTechnical Trade-offs
Author's notes

Short answer: separate signal.

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AI HintsAI Generated

Suggested Approach

Start by clarifying the purpose of the weekly primary KPI versus an alerting signal, then argue that a separate, more granular signal is needed for timely harm detection. Propose a concrete design for the alerting signal, including its definition, threshold, and monitoring cadence, and explain how it complements the primary KPI.

Pro tip: Emphasize that alerting signals should be designed for actionability and low false positives, not for comprehensive measurement—this shows you understand the operational realities of on-call systems.

1. Clarify the KPI's role

Explain that the weekly primary KPI is a strategic metric for tracking long-term progress, not for real-time operational monitoring. Its weekly cadence and aggregation make it too slow and noisy for triggering alerts.

2. Identify alerting requirements

Define what an alerting signal needs: high sensitivity to harm spikes, low latency (e.g., daily or hourly), low false positive rate, and clear actionability for on-call engineers.

3. Design the alerting signal

Propose a separate signal, such as a daily harm rate (e.g., percentage of users experiencing harm) with a statistical process control threshold. Include specifics: metric definition, data source, aggregation window, and alert threshold.

4. Validate and iterate

Suggest backtesting the signal on historical data to tune thresholds, and monitoring its performance (e.g., precision/recall) after deployment. Mention the need for periodic review to avoid alert fatigue.

5. Align with stakeholders

Highlight the importance of collaborating with engineering, product, and on-call teams to ensure the signal is actionable and integrated into existing incident response workflows.

Key Points to Mention

  • Difference between strategic KPIs and operational alerting metrics
  • Latency and granularity requirements for harm detection
  • Statistical process control or anomaly detection methods
  • False positive/negative trade-offs and alert fatigue
  • Actionability and clear ownership for on-call response
  • Backtesting and continuous improvement of alert thresholds

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

Q7

How would you set severity weights across violation policy classes in a defensible way, and how would you detect if those weights are driving misleading movements in the KPI?

Product Analytics & MetricsTechnical Trade-offsCross-functional Alignment
Author's notes

I said the weights should come from a combination of policy team input (which harm types are highest priority) and empirical signals like downstream harm rates per violation class (reports, account deactivations, legal escalations).

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AI HintsAI Generated

Suggested Approach

Start by framing severity weights as a policy decision that must be grounded in harm, precedent, and stakeholder alignment, not just data. Then describe a validation framework that monitors KPI movements for anomalies, checks for unintended incentives, and uses sensitivity analysis to ensure weights are defensible.

Pro tip: Proactively mention that you would document the rationale for each weight and set up a regular review cadence with policy, legal, and product teams—this shows you understand the cross-functional nature of trust & safety metrics.

1. Define harm and policy objectives

Collaborate with policy and legal teams to classify violations by type and severity, using frameworks like harm to users, platform integrity, and regulatory risk. Establish clear principles (e.g., proportionality, consistency) to guide weight assignment.

2. Assign initial weights using a defensible method

Use a combination of expert judgment (e.g., Delphi method), historical enforcement data, and external benchmarks to set initial weights. Document assumptions and ensure weights are on a consistent scale (e.g., 1-10) with clear anchors.

3. Validate weights via sensitivity and scenario analysis

Test how KPI movements change under different weightings (e.g., Monte Carlo simulations, stress tests) to identify which weights drive the most volatility. Check for unintended consequences like over-penalizing minor violations.

4. Monitor KPI for misleading movements

Set up dashboards with control charts and anomaly detection to flag sudden shifts. Decompose KPI changes into volume vs. severity components to see if weights are causing artificial spikes or drops.

5. Iterate with cross-functional review

Establish a regular review process with policy, legal, product, and data science to reassess weights based on new evidence, societal norms, and business goals. Use A/B testing or holdout groups to measure impact of weight changes.

Key Points to Mention

  • Grounding weights in harm reduction and policy objectives, not just data convenience
  • Using a transparent and documented methodology (e.g., expert panels, historical analysis)
  • Performing sensitivity analysis to understand KPI volatility and weight impact
  • Decomposing KPI movements to separate volume effects from severity weight effects
  • Setting up anomaly detection and control charts to catch misleading trends
  • Cross-functional alignment and regular review to keep weights defensible over time

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

Q8

An intervention reduces your primary metric but you suspect creators are migrating to a less-instrumented surface like DMs. How do you detect and account for surface displacement?

Product Analytics & MetricsRoot Cause AnalysisSystem Design
Author's notes

Classic whack-a-mole problem.

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AI HintsAI Generated

Suggested Approach

First, acknowledge the risk of surface displacement and propose a systematic detection plan using cross-surface metrics and user-level analysis. Then, outline how to quantify the migration and adjust the primary metric to account for it, ensuring the intervention's true impact is measured. Emphasize the importance of instrumentation and experimentation to validate hypotheses.

Pro tip: Proactively suggest setting up a holdout group or a switchback experiment to measure displacement effects, and mention the need to instrument DMs or other surfaces if not already tracked. This shows you think about long-term measurement strategy, not just immediate analysis.

1. Define and Instrument Surfaces

Identify all potential surfaces where creators might migrate (e.g., DMs, groups, external platforms) and ensure they are instrumented to capture relevant actions. If not, advocate for logging or use proxies like server logs or surveys.

2. Detect Displacement Signals

Analyze cross-surface metrics: compare trends in the primary metric with complementary metrics on other surfaces (e.g., DM volume, response rates). Look for anomalies or inverse correlations at the user level.

3. Quantify Migration

Estimate the extent of migration using user-level data: track creators who decreased activity on the primary surface and increased on others. Use cohort analysis or difference-in-differences to attribute changes.

4. Adjust Primary Metric

Create a composite metric that combines activity across surfaces, or model the counterfactual to estimate what the primary metric would have been without displacement. Validate with experiments if possible.

5. Validate and Monitor

Run follow-up experiments (e.g., holdout, switchback) to confirm displacement and measure the adjusted impact. Set up ongoing monitoring to detect future displacement.

Key Points to Mention

  • Cross-surface analysis and user-level tracking
  • Instrumentation gaps and proxies for unlogged surfaces
  • Difference-in-differences or cohort analysis to quantify migration
  • Composite metrics or counterfactual modeling to adjust primary metric
  • Experimental validation (holdout, switchback) to confirm displacement
  • Long-term monitoring and metric governance

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