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
Evaluate food-court profitability and membership strategy
Diagnose Flight Delays and Burger Launch
Design analysis to test social vs game engagement
Design robust experiment for ambiguous core change
Evaluate impact without randomized experiments
Design A/B Test for Streaming Feature Network Effects
Evaluate 'Job You May Be Interested In' Recommender
Design ad revenue A/B with guardrails
Define and analyze product metrics
Test If Initial Video Uploads Are Shorter Than Later Ones
Single Queue vs Multiple Queues — Service Design
Investigate LA successful orders drop
Design a robust email A/B test
Implement Clustered Sampling to Mitigate Network Effects in Testing
Evaluate Recommendation Feature with Historical Data Analysis
One of the most comprehensive LinkedIn DS Product Cases!
Assess Demand for Group Video Chat
Define Ultra success and detect suspicious transactions
How would you decide to cancel a TV show?
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.