A/B Testing Interview Questions
A/B testing questions are central to data science and product analytics interviews at companies like Meta, Google, Netflix, and Airbnb.
Expect questions on experiment design, randomization units, sample size calculation, multiple comparisons, and metric selection.
Interviewers evaluate your statistical rigor, practical judgment, and ability to communicate experiment results.
Common A/B testing interview patterns
- Designing an experiment for a product change
- Calculating sample size and experiment duration
- Choosing between one-sided and two-sided tests
- Handling multiple comparisons and peeking
- Interpreting results with novelty or primacy effects
- Network effects and interference between test groups
A/B testing interview questions
Design and backtest a trading strategy
Diagnose Causes and Test Hypotheses for Metric Drop
Design station experiment with interference and rush-hour spillovers
Define and measure article trending
Evaluate Push Notification Impact on Rideshare Supply Shortages
How to Design Effective A/B Tests for Onboarding
Design an A/B test for promo-targeting models
Define Success Metrics and Experiment Plan for Product Development
Analyze Causes of November and June Shopify Traffic Spikes
Assess LinkedIn Newsfeed Health
Design experiments for marketplace product changes
Design and evaluate a new group call feature
Define ride success metric for Uber
Improve Profile Completion Rate
Determine Success Metrics for New Group Video-Call Feature
Compute p-values for 2 variants vs control
Diagnose cold-food spike and design experiments
Evaluate and test a Top Dasher program
Evaluate AI-assisted ads creation feature
Common mistakes in A/B testing interviews
- Not specifying the randomization unit (user vs session vs page)
- Peeking at results before reaching the required sample size
- Ignoring practical significance when statistical significance is achieved
- Not considering guardrail metrics
- Failing to account for novelty effects in short experiments
How A/B testing questions are evaluated
Structure your experiment design: hypothesis, metrics, unit, sample size, duration.
Discuss what could go wrong and how you would detect it.
Show ability to make a recommendation even when results are ambiguous.
Related analytics concepts
A/B Testing Interview FAQs
How do you determine the sample size for an A/B test?
Use a power analysis with inputs: baseline metric, minimum detectable effect (MDE), significance level (alpha, usually 0.05), and power (usually 0.80). Larger effects need fewer samples. For small MDE on rare events, you may need millions of users.
What is the difference between statistical and practical significance?
Statistical significance means the observed difference is unlikely due to chance (p-value < alpha). Practical significance means the effect is large enough to matter for the business. A statistically significant 0.01% lift may not be worth the engineering cost to ship.