Product analytics and experiments
Event and tracking design
- One event = one user action with stable name and versioned schema.
- Required context:
user_idor anonymous id,timestamp,session_id, product surface. - Document in a tracking plan: event, properties, trigger, owner, PII classification.
Core metrics
| Type | Examples |
|---|---|
| Acquisition | Signups, activation rate |
| Engagement | DAU/WAU, feature adoption |
| Conversion | Funnel step rates |
| Retention | D1/D7/D30 cohort retention |
| Quality | Error rate, task success |
Define denominator explicitly (eligible users, not all traffic).
Funnel analysis
- Define steps and entry criteria.
- Check identity stitching and time window.
- Segment by platform, cohort, campaign (avoid Simpson's paradox surprises).
A/B test gates (before launch)
- Hypothesis and primary metric (one primary)
- Guardrail metrics (latency, errors, revenue risk)
- Randomization unit correct (user vs session)
- Sample size / MDE estimated; duration planned
- No peeking-driven early stop without sequential plan
- Feature flags and exposure logging verified in staging
Analysis
- Intent-to-treat as default; document exclusions.
- Report: point estimate, CI, practical significance (not only p-value).
- Slice only with pre-registration or clear exploration label.
Anti-patterns
- Changing primary metric after results visible.
- Multiple simultaneous experiments on same surface without interaction analysis.
- Tracking PII without legal/product review.
Output
Experiment brief: hypothesis, design, metrics, ship/kill criteria, results template.