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 Conversion Drop: Metrics, Analyses, Techniques Explained
LinkedIn Product Case Opportunity Sizing
Assess free-month promotion impact
How would you compare Facebook vs Instagram Stories?
Experimentally evaluate jogging-route recommendations
How would you evaluate pixel-issue notifications?
Measure Impact of Merchant Variety on Consumer Experience
Design a pricing experiment with network effects
Improve Estimated Time of Arrival for Uber Riders
Design "Restaurants You May Know" Recommendation Algorithm
Design an RCT for app-open discount
Evaluate Auto-Play Impact with Key Metrics and Experiment Design
Analyze and mitigate fake advertiser accounts
Plan and analyze a ranking A/B test
Estimate Causal Impact Using Synthetic Control Methods
Boost App Installs: Analyze and Experiment with Conversion Funnel
Identify Potential Users for Instagram Shopping Tab Adoption
Compare performance of FB vs IG Stories
Compute duration and stopping rules correctly
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.