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    Challenge Library/Should We Ship the Recommendation Algorithm?

    Should We Ship the Recommendation Algorithm?

    data science
    experimentation
    statistics
    B2B/consumer
    Estimated Time:
    45 minutes
    Status:Not started

    What You'll Be Doing

    Description

    You're joining Fathom as their first Senior Data Scientist. Fathom is a subscription fitness app with 340,000 paying subscribers. The Growth team just ran an A/B test on a new workout-recommendation algorithm and is ready to ship it to 100% of users — they've already reallocated next quarter's roadmap assuming it ships.

    The VP of Product has asked you to review the results before final sign-off: "This looks like a clear win to Growth. I need your read before I take it to the board in a week."

    The experiment data:

    MetricTreatment (new algorithm)Control (existing algorithm)
    Users82,00081,400
    Test duration9 days9 days
    Weekly active minutes (primary metric)+4.2% vs. control (p = 0.008)—
    Revenue per active user, 7-day−0.3% vs. control (p = 0.61, not significant)—
    Support tickets tagged "recommendations felt repetitive/irrelevant"+18% vs. control—
    Engagement lift, users with <30 days tenure+9.1%—
    Engagement lift, users with >90 days tenure−1.2% (not significant)—
    Number of secondary engagement metrics tested14 total; this is the only one significant at p < 0.05—

    Additional context: The Growth team's own postmortems on the last three recommendation-algorithm experiments found that engagement lifts from launch-week tests faded to statistically null within roughly three weeks of full rollout in two of the three cases.

    You have 45 minutes to form your recommendation.

    Constraints to Consider

    • No further testing before the decision: The board conversation is in one week. You cannot extend the experiment or run a follow-up test before you need to give your recommendation.
    • No new data collection: You have the experiment logs and the historical postmortem summaries above — no ability to instrument new metrics or pull additional segments before the deadline.
    • Reversing course has a real cost: Growth has already reallocated next quarter's roadmap assuming this ships. A "don't ship" or "ship partially" recommendation is not free — it has planning and political cost, and you should account for that honestly rather than ignoring it.
    • The board is expecting a decision, not a request for more time: Leadership has already told the board a call would be made this quarter. "We need to gather more data" is not an acceptable recommendation on its own.
    • You do not own the recommendation model's implementation — you are being asked for your analytical judgment and recommendation, not a technical redesign of the algorithm itself.

    AI Usage Guidance

    We expect you to use AI tools. We evaluate how you use them — not whether you use them. Evidence of iteration, redirection, and critical evaluation scores higher than a polished output with no process documentation.

    The single highest-signal indicator: your video answer to the mandatory AI question. If you cannot name a specific moment where you redirected AI output, evaluators will assume you did not.

    Mandatory AI question for your video: Walk me through one moment where you disagreed with, pushed back on, or redirected what the AI gave you — and what you did instead. Name the specific moment. Explain what the AI produced that didn't meet the bar, what you did differently, and why.

    Video guidance for this role: Speak naturally, as if you're briefing the VP of Product directly. We're listening for the quality of your statistical judgment and your honesty about what the data does and doesn't support — not verbal polish.

    Submission: Upload each deliverable as a separate file directly on the Provn platform: your Analysis & Recommendation Memo, your README document (Sections A, B, and C), and your video walkthrough (MP4 or MOV).

    What You'll Accomplish

    Demonstrate the ability to diagnose validity threats in an experiment result from imperfect, aggregate data

    Translate a statistical finding into a specific, actionable business recommendation with an honest confidence statement

    Show honest engagement with a result that complicates the "obvious" conclusion, not a smoothed-over success narrative

    Connect a recommendation to a post-launch monitoring plan anchored to the scenario's own data

    Show how you worked with AI to accelerate your process — including at least one moment where you redirected it

    How Your Work Will Be Scored

    Statistical & Experimental Rigor (30%): A strong submission identifies a scenario-specific validity threat (novelty effect, segment heterogeneity, multiple comparisons) and proposes an evaluation approach with a guardrail metric, not just an endorsement of the topline result.Model & Solution Design (25%): A strong submission frames the actual business decision, names an explicit trade-off, and honestly reconciles the engagement lift with the flat/negative revenue signal rather than ignoring it.Business Communication & Stakeholder Translation (20%): A strong submission delivers a specific, actionable recommendation with a stated confidence level and anticipates the Growth team's pushback.Production & Deployment Judgment (10%): A strong submission names a specific post-launch risk and a monitoring threshold anchored to a number in the data package.AI Fluency (15%): A strong submission documents at least 2 honest AI interactions in the usage log and answers the video AI question with a specific named redirection moment — not a generic description of "reviewing AI output."

    What to Submit

    No submission guidelines provided.

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