Instrumentation Spec Growth

instrumentation-spec-growth

Agent: Growth Engineer

L2 growth engineer (Nx) responsible for growth instrumentation, metrics dashboards, funnel analysis, and growth loop activation.

Department ethos: ideal-data-growth.md

Skill Description

The growth instrumentation spec writer produces the authoritative document defining every growth-specific event — channel attribution, experiment assignment, funnel step completion, loop node actions, and retention signals — with property schemas, data types, and trigger conditions so that every growth metric and experiment can be computed from the captured data.

When to Use

• When growth experiments are planned and need tracking event definitions before implementation.
• When the growth funnel lacks consistent event coverage across acquisition, activation, and retention stages.
• When a new growth loop is designed and each node needs event specification.
• When the growth team migrates to a new experimentation or analytics platform and events need re-specification.

Workflow

1. Gather growth measurement requirements: Extract every growth metric, experiment goal, and funnel step from the growth model, experiment roadmap, and loop designs. List the queries the spec must support.
2. Define acquisition events: Specify events for first touch, landing page view, UTM capture, signup started, signup completed. Include attribution properties (utm_source, utm_medium, utm_campaign, referrer).
3. Define activation events: Specify events for each onboarding step and the activation moment. Include properties for time-to-complete and cohort assignment.
4. Define experiment events: Specify experiment_assigned (experiment_id, variant_id, user_id, timestamp) and goal events for each active and planned experiment.
5. Define loop events: For each growth loop, specify trigger impression, trigger action, distribution event, referred user events, and reward events with referrer_id linkage.
6. Define retention events: Specify session start, key engagement actions, and re-engagement trigger events (email opened, push clicked, re-activated).
7. Map events to metrics: Create a traceability matrix linking each growth metric to the events required to compute it. Identify gaps and add events to close them.
8. Submit for review: Send the spec to the instrumentation clarity reviewer for approval before implementation begins.

Anti-Patterns

• Duplicating product events: Re-specifying events that already exist in the product instrumentation spec creates duplicate data and naming conflicts. Why: use existing product events and extend with growth-specific properties rather than creating parallel event streams.
• No experiment event standard: Specifying experiment events inconsistently across experiments makes cross-experiment analysis impossible. Why: a standard experiment_assigned schema enables the significance tracker to process any experiment uniformly.
• Missing referrer linkage: Specifying referral events without a consistent referrer_id property breaks loop attribution. Why: without the link between referrer and referred user, viral coefficient is uncomputable.
• Ignoring consent requirements: Specifying user-level tracking without consent gating violates privacy regulations in opt-in jurisdictions. Why: non-compliant tracking creates legal risk and may require retroactive data deletion.

Output

Success:

• A growth instrumentation spec with acquisition, activation, experiment, loop, and retention event definitions, property schemas, traceability matrix, and clarity reviewer approval.

Failure:

• The spec has gaps that prevent a growth metric from being computed. Report the uncomputable metric, the missing events, and the additions required.

Related Skills

• instrumentation-spec-data -- the product instrumentation spec that growth events extend rather than duplicate.
• instrumentation-implementer-growth -- implements the events defined in this spec.
• instrumentation-clarity-reviewer -- reviews this spec for completeness and measurability.
• growth-model-designer -- the growth model's metrics drive the measurement requirements this spec fulfils.