audit-analytics — Product-event instrumentation

Degree of freedom: HIGH — judgment on taxonomy and funnel coverage. Consent-gate proof is [LOW freedom] when you confirm the SDK does not init on boot (quote the init site; do not invent a legal opinion).

Read-only. You verify the app measures what the business needs to decide, with one taxonomy, without leaking PII or firing before consent.

The failure mode is silent: the dashboard looks populated, but the key funnel step was never instrumented, so every decision on it is guesswork.

Present findings. Propose a canonical taxonomy. Do not rewrite events until approved.

This skill vs neighbors

Do not fire for "build me a chart" → data-visualization. Do not fire for "GDPR / privacy labels" alone → plan-privacy-compliance (then come back here for the event matrix).

How to reason

1. Observe — quote the track() / schema name and where it fires
2. Interpret — can the business answer the funnel question this event claims to answer?
3. Classify — missing / dead / duplicate / phantom / PII / consent-before-init / correct
4. Severity — key-funnel step never fired, or analytics before consent = P0

Worked example

Observe: signup success fires signup_completed on web and Signup Success on iOS; PostHog inits in layout.tsx before the consent banner. Interpret: the funnel splits across two names; EU visitors are tracked before consent. Classify: taxonomy split + consent-before-init. Severity: P0 for consent; major for the name split. Finding: Signup Success | duplicate name | unify to signup_completed; init → plan-privacy-compliance + gate behind consent.

Phase 0 — Detect the analytics stack [HIGH freedom]

• Provider: PostHog / Amplitude / Mixpanel / GA4 / Segment / custom table
• Where events are defined: central taxonomy vs scattered track() (scattered is itself a finding)
• Typed schema vs free-form string names
• Web vs iOS vs Android vs server

Phase 1 — Reconstruct the intended funnel [HIGH freedom]

From the product's core loop, list critical journeys as ordered steps (e.g. install → signup → activation → first value → habit → conversion). For each step, name the event(s) that must fire. This is the yardstick.

Phase 2 — Coverage and correctness [HIGH freedom; consent init = LOW]

Funnel completeness — Each intended step has an event in code. Missing Y means you cannot answer "why drop between X and Y".

Taxonomy — One convention (object_action, case, tense). Mixed names (signup_completed vs Signup Success) fragment analysis. Properties consistent (user_id vs userId).

Dead / duplicate / phantom — Defined never fired; same action twice under different names; fired on render instead of on action.

Property hygiene — Plan tier, platform, source present so cohorts work later.

PII & consent — No raw email/name/address in properties. Analytics SDK gated behind consent — not initialized on boot. Cross-check plan-privacy-compliance for the legal inventory; this skill owns the event-level gate.

Cross-platform parity — Same action → same event name on each client.

Identity — Anonymous → identified stitch after signup. Broken stitch double-counts users.

Definition of Done

• Intended funnel(s) written with required event per step
• Each step instrumented or gap logged
• Naming checked against one convention
• Dead, duplicate, phantom fires listed
• PII in properties + consent-gating verified; privacy handoff written
• Cross-platform parity checked if multi-platform
• Anonymous→identified stitching verified
• Nothing rewritten without approval

Self-critique before reporting [LOW freedom — do not skip]

1. Evidenced — event name + file:line, not "we probably track signup"
2. Funnel first — every finding maps to a step that must fire
3. No PII values — report property names, never emails or user ids
4. Right owner — legal inventory → plan-privacy-compliance
5. Nothing rewritten — taxonomy proposed, not applied

Output format

1. Funnel coverage — step | required event | present? | notes
2. Taxonomy findings — inconsistent/dead/duplicate/phantom | severity | fix
3. PII/consent — event | problem | handoff to plan-privacy-compliance
4. Fix plan — taxonomy → missing events → consent gate, severity-ordered

Related

• plan-privacy-compliance — consent, deletion, store labels (run both)
• iterate-post-launch — consume a trustworthy data layer
• audit-ux-journeys — journeys that need funnel evidence
• data-visualization — rendering metrics, not collecting them
• workflow-feature-flag — flag exposure events