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Amazon·Software Engineer·Technical Phone Screen·Intermediate

Intermediate
Apr 2026

Summary

Amazon interview question about experiment design and metric selection. Not much context on the role but felt like a data science or product analytics screen.

Questions Asked (1)

Q1

When designing an experiment, how do you decide which metrics to track? What separates a good metric from a bad one?

A/B Testing & ExperimentationProduct Analytics & Metrics
Author's notes

This tripped me up more than I expected.

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AI HintsAI Generated

Suggested Approach

Start by tying metrics to the experiment's hypothesis and business goal, then categorize them into success, guardrail, and diagnostic metrics. Explain that good metrics are actionable, sensitive to change, and aligned with long-term objectives, while bad metrics are vanity, ambiguous, or easily gamed.

Pro tip: Emphasize the importance of guardrail metrics to catch unintended consequences, and mention that at Amazon, metrics should be customer-centric and tied to input measures that teams can directly influence.

1. Define the hypothesis and goal

Clearly articulate what you're testing and the expected outcome. This ensures metrics are directly tied to the experiment's purpose.

2. Choose a primary success metric

Select one key metric that best represents the desired outcome and is sensitive enough to detect a meaningful change.

3. Add guardrail metrics

Identify metrics that should not degrade, such as latency, error rates, or customer satisfaction, to monitor unintended side effects.

4. Include diagnostic metrics

Pick additional metrics to help explain why the primary metric moved, such as click-through rates or conversion funnels.

5. Evaluate metric quality

Assess each metric against criteria like actionability, sensitivity, and alignment with long-term goals to separate good from bad.

Key Points to Mention

  • Alignment with business objectives and customer value
  • Actionability: can you make decisions based on the metric?
  • Sensitivity: does the metric detect meaningful changes?
  • Guardrail metrics to prevent negative side effects
  • Avoiding vanity metrics (e.g., total page views) and metrics that are easily gamed
  • Considering long-term impact vs. short-term gains

AI-generated suggestions, not part of the candidate's original notes. May be inaccurate — verify before relying on them.