Design an A/B test for a new checkout flow
Last updated: February 1, 2026
Quick Overview
Design an experiment to test the impact of a redesigned homepage. Include sample size calculation, metrics, and analysis plan.
NVIDIA
February 1, 2026116
6
143 solved
Design an experiment to test the impact of a redesigned homepage. Include sample size calculation, metrics, and analysis plan.
This analytics question from NVIDIA's Phone Screen tests your ability to think critically about data. The interviewer expects you to consider confounding variables, selection bias, and the difference between correlation and causation.
What the Interviewer Expects
- Design complex experimentation strategies for tricky scenarios
- Handle multi-armed bandits, switchback experiments, and quasi-experiments
- Address long-term effects vs short-term metrics
- Propose causal inference methods when randomization is not possible
- Build a measurement framework that connects metrics to business value
- Discuss organizational experimentation culture and maturity
Key Topics to Cover
How to Approach This
- Define success metrics carefully. A good metric is measurable, actionable, and aligned with business goals.
- Run experiments long enough to account for novelty effects and weekly seasonality.
- Use funnel analysis to identify where users drop off for maximum optimization impact.
- Segment results by key dimensions (platform, country, user cohort) to catch hidden patterns.
- Consider network effects and interference between treatment and control groups.
Possible Follow-up Questions
- How would you handle seasonality in your experiment?
- What would you do if a stakeholder wants to end the experiment early because initial results look good?
- What if the experiment shows a positive short-term effect but you suspect a negative long-term impact?
- How would you handle an experiment where the control and treatment groups are different sizes?
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Browse Analytics QuestionsSample Answer
Problem Setup
The primary analytical question is: "Does the redesigned homepage increase the conversion rate for purchases?" To answer this, I would need data on user interactions with both the current and redesign...
Methodology
To design the A/B test, I would use a randomized controlled trial approach where:
- Users visiting the website are randomly assigned to either the control group (current homepage) or the treatment gr...
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