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
Investigate Sudden Revenue Drop: Steps and Metrics Analyzed
Improve TikTok's Algorithm for Diverse Content Discovery
How to evaluate a new homepage feature
Establish causality: commute playlist and driving speed
Assess education–income effect credibly
Investigate SMS delivery-rate drop at Attentive
Design A/B test for credit card offer
Detect and evaluate "stolen" posts
Identify Growth Opportunities for New Payroll Feature Launch
Investigate Pop-up Impact on Partner Referral Conversions
Design an A/B Test for Homepage Layout Impact
Predict Impact of 'Online Indicator' Feature
Evaluate UberEATS priority delivery and membership
How would you evaluate UberEats growth?
Measure speaker impact without A/B testing
Design an interference-robust A/B test for monetization
Identify Key Metrics to Address Delivery Delays
Expected impressions per user under random assignment
How to debug an apparent D14 retention drop
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.