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 Optimal Dasher Compensation Model and Diagnose Metric Drops
Determine Player Preference for Local Game Creators
Design A/B Test for Marketing Campaign Impact Evaluation
Track Metrics to Measure Push Notification Quality
Analyze Factors Behind 20% Retail Revenue Decline
Design and validate an ads feed experiment
Design an experiment for order batching
Define and Measure Merchant Variety's Impact on Consumers
Design an experiment for pricing page redesign
Diagnose KPI anomaly and evaluate promotion/A-B test
Resolve Conflicting A/B Test Results in Cities
Identify Sales Professionals
Should WhatsApp Launch Group Calls?
Measure Shopify App Store Launch Success Effectively
Assessing whether a new metric A is meaningful for News Feed
How to evaluate lowering ETA?
Diagnose completed orders drop in Los Angeles
Design and analyze batching algorithm experiment
Define product success 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.