PracHub
QuestionsPremiumCoachesLearningGuidesInterview Prep
|Home/Analytics & Experimentation/Meta

Design A/B test and success metrics for new feature

Last updated: Mar 29, 2026

Quick Overview

This question evaluates a data scientist's competency in experimental design, metric selection and guardrails, power and sample-size calculations, logging and attribution specifications, and revenue impact estimation for a new feature on a social media platform.

  • hard
  • Meta
  • Analytics & Experimentation
  • Data Scientist

Design A/B test and success metrics for new feature

Company: Meta

Role: Data Scientist

Category: Analytics & Experimentation

Difficulty: hard

Interview Round: Onsite

You are proposing a new Instagram feature: shareable Collections 2.0 meant to increase creator activity and monetization. Define success and guardrails: - State the mission and primary North Star metrics (one for engagement, one for revenue) and at least three counter metrics to protect experience and integrity. Design the experiment: - Choose user-level or geo-clustered A B test and justify considering network effects and contamination. Propose a stratification scheme using deciles of an engagement score and outline the randomization and ramp plan. - With baseline D30 retention 30% and a target 1% relative lift, compute the required sample size per arm at 90% power and alpha 0.05. State assumptions and formula. - Define stopping rules, pre-registration, and guardrail thresholds such as crash rate and time spent. Measurement and decisioning: - Specify the exact logging spec and how you would attribute revenue. Given average 4 ad impressions per DAU, CTR 1%, and revenue per ad click 0.50 dollars, estimate weekly incremental revenue if the feature increases ad clicks by 2% on 100 million DAUs. Include sensitivity and uncertainty bands. - List reasons not to launch even with statistically significant wins, including technical feasibility and long-term costs.

Quick Answer: This question evaluates a data scientist's competency in experimental design, metric selection and guardrails, power and sample-size calculations, logging and attribution specifications, and revenue impact estimation for a new feature on a social media platform.

Related Interview Questions

  • Measure scheduled posts feature success - Meta (medium)
  • Estimate ads ranking revenue impact - Meta (medium)
  • How should you evaluate unconnected content? - Meta (medium)
  • Should WhatsApp launch group calls? - Meta (medium)
  • How would you grow Meta products? - Meta (medium)
Meta logo
Meta
Oct 13, 2025, 9:49 PM
Data Scientist
Onsite
Analytics & Experimentation
5
0

Instagram Collections 2.0 — Define Success, Experiment Design, and Measurement

Context: You are proposing a new Instagram feature, Shareable Collections 2.0, intended to increase creator activity and monetization. Design how you would define success, run the experiment, and decide whether to launch.

1) Define Success and Guardrails

  • State the mission and choose primary North Star metrics (one engagement metric, one revenue metric).
  • List at least three counter metrics to protect user experience and integrity.

2) Design the Experiment

  • Choose user-level A/B test or geo-clustered A/B test and justify your choice considering network effects and contamination.
  • Propose a stratification scheme using deciles of an engagement score. Outline randomization and a ramp plan.
  • With baseline D30 retention = 30% and a target 1% relative lift, compute the required sample size per arm at 90% power, alpha = 0.05. State assumptions and the formula you use.
  • Define stopping rules, pre-registration plan, and guardrail thresholds (e.g., crash rate, time spent).

3) Measurement and Decisioning

  • Specify the exact logging spec (key events and fields) and how you would attribute revenue.
  • Given: average 4 ad impressions per DAU, CTR = 1%, revenue per ad click = $0.50. If the feature increases ad clicks by 2% on 100M DAUs, estimate weekly incremental revenue. Include sensitivity and uncertainty bands.
  • List reasons not to launch even if the test shows statistically significant wins (cover technical feasibility and long-term costs).

Solution

Show

Submit Your Answer to Earn 20XP

Sign in to leave a comment

Loading comments...

Browse More Questions

More Analytics & Experimentation•More Meta•More Data Scientist•Meta Data Scientist•Meta Analytics & Experimentation•Data Scientist Analytics & Experimentation
PracHub

Master your tech interviews with 8,000+ real questions from top companies.

Product

  • Questions
  • Learning Tracks
  • Interview Guides
  • Resources
  • Premium
  • For Universities
  • Student Access

Browse

  • By Company
  • By Role
  • By Category
  • Topic Hubs
  • SQL Questions
  • Compare Platforms
  • Discord Community

Support

  • support@prachub.com
  • (916) 541-4762

Legal

  • Privacy Policy
  • Terms of Service
  • About Us

© 2026 PracHub. All rights reserved.