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
Determine Group Call Feature Need and Evaluation Methods
Track Success and Guardrail Metrics for Push Notifications
Evaluate Metrics and Randomization for Onboarding Tutorial Change
Validate Friend Content's Social Impact with Engagement Metrics
Investigate Traffic Distribution Impact on Retention Decrease
Investigate Causes of Cold Food Deliveries and Solutions
Measure Success of New B2B Product
Design an A/B test for search ranking
Measure Impact of Updated Rider ETA Algorithm
How would you diagnose a completed orders drop?
Estimate causal effect with interference
Explain Algorithm's Disproportionate Impact on Demographic Segments
Design A/B Test for New Recommendation Algorithm Launch
How to experiment on ETA reduction
Modify Instagram Feature: Track User Engagement Metric
Determine Metrics to Measure Free-Trial Impact on Subscriptions
Apply Multiple Testing Corrections for Valid Results Analysis
Validate Friends' Content Engagement with Experimental Design Metrics
Evaluate Home-Feed Diversity's Impact on User Engagement Metrics
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.