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Reddit·Machine Learning Engineer·Onsite - Product Sense / Strategy·Senior

Senior
Jun 2026

Summary

Reddit ML Engineer interview with a product-sense style question that felt a bit out of left field for the role. One question, pretty open-ended, and I left unsure whether I'd framed it the right way for an MLE position versus a PM one.

Questions Asked (1)

Q1

How would you redesign the onboarding experience for new users on a community platform like Reddit, covering friction identification, success metrics, prioritization, and experiment design?

Product Analytics & MetricsA/B Testing & ExperimentationProduct Sense & Ideation
Author's notes

Spent the first few minutes trying to figure out whether they wanted an MLE answer or a PM answer.

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AI HintsAI Generated

Suggested Approach

Start by framing onboarding as a funnel with clear stages (sign-up, first visit, first action, retention) and identify friction points at each stage using data and user research. Then define success metrics tied to long-term retention and engagement, prioritize the biggest friction points by impact and effort, and design A/B tests to validate solutions. As an ML engineer, emphasize how ML can personalize and optimize the onboarding flow.

Pro tip: Tie every proposed change to a measurable metric and show how you'd use ML to personalize the experience at scale, but always validate with experiments before full rollout. Also, consider the cold-start problem for new users and how ML can mitigate it.

1. Map the onboarding funnel and identify friction

Break down the onboarding journey into stages (e.g., landing, sign-up, interest selection, first post/comment/vote) and use data (drop-off rates, time spent) and qualitative research to pinpoint friction points.

2. Define success metrics

Choose metrics that reflect both immediate onboarding success (e.g., completion rate, time to first action) and long-term outcomes (e.g., D7/D30 retention, posts per user). Ensure they align with Reddit's goals.

3. Prioritize friction points

Use a framework like RICE or impact/effort to rank friction points. Consider factors like user impact, business value, and technical feasibility, especially for ML solutions.

4. Design experiments and ML interventions

Propose A/B tests for each prioritized change, with clear hypotheses, control/treatment groups, and success criteria. For ML, suggest personalization (e.g., recommending communities) and measure its incremental impact.

5. Iterate and scale

Analyze experiment results, iterate on winning variants, and plan for scaling successful ML models while monitoring for long-term effects and potential biases.

Key Points to Mention

  • Funnel analysis and drop-off points in onboarding
  • Metrics: activation rate, time to first action, D7/D30 retention
  • Prioritization frameworks like RICE or impact/effort matrix
  • A/B testing methodology: hypothesis, randomization, sample size, guardrail metrics
  • ML applications: personalized community recommendations, content suggestions, and cold-start solutions
  • Ethical considerations: avoiding filter bubbles, ensuring diversity in recommendations

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