Compare performance of FB vs IG Stories
Company: Meta
Role: Data Scientist
Category: Analytics & Experimentation
Difficulty: easy
Interview Round: Technical Screen
You are asked to compare ads performance between two placements/products (e.g., **Facebook Stories vs Instagram Stories**) and make a recommendation on where to allocate budget.
### Task
Describe how you would conduct a fair comparison, including:
1. What **primary metric** you’d optimize for (and why), plus diagnostic and guardrail metrics.
2. How you’d handle **attribution** and cross-platform user overlap (same user on both).
3. Key confounders (audience differences, auction dynamics, creative fit, seasonality).
4. Whether you’d use observational analysis or a controlled experiment; design the experiment if applicable.
5. How you’d present results and decide budget allocation under uncertainty.
Assume you have impression-, click-, and conversion-level logs and cost data.
Quick Answer: This question evaluates a data scientist's competency in experimental design, causal inference, attribution modeling, metric selection, and decision-oriented statistical analysis within the Analytics & Experimentation domain.