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
Analyze Trends to Optimize Pirate-Theme Product Strategy
Evaluate an ads algorithm change
Evaluate channels and allocate budget
Balance Customer Satisfaction with Fraud Prevention: Key Metrics to Track
Analyze Call Drop Rates Pre- and Post-Update Implementation
Investigate Instacart Revenue Decline Using Weekly Data
Analyze Impact of Customer Reviews on Sales Performance
Evaluate Dasher Initiatives with A/B Testing and Metrics
Analyze private-account product metrics
Evaluate College Impact on Income: Address Bias and Validity
Plan and validate ranking experiment
Design and power a frequency-cap experiment
Investigate Causes of Increased Driver Wait Time
Track Key Metrics for Apple's New Phone Launch
Interpreting confidence intervals to choose a treatment
Investigate Yahoo Mail's 10% DAU Decline Causes
Analyze Negative Reviews' Impact on Coupon Repurchase Rate
How to Target Coupon Users
Investigate Anomalies in Coinbase Wallet 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.