The tracking plan that governs a CDP
Segment end-to-end: event design, identity resolution, server-side GTM, and the governance that keeps it clean.
Overview
Designed and implemented a comprehensive tracking plan and CDP architecture using Segment, covering event taxonomy, identity resolution, server-side Google Tag Manager, and ongoing governance.
Problem
Marketing data was fragmented across tools with no unified event schema, inconsistent user identity across touchpoints, and no governance process to prevent tracking drift over time.
Constraints
- Must unify data across web properties, ad platforms, and CRM
- Consent management (Consent Mode v2) required for compliance
- Tracking plan must be maintainable by non-technical marketing team members
Approach
Built a Segment-centered CDP with a governed event taxonomy, identity resolution rules, server-side GTM for reliable data collection, and a documented tracking plan that serves as the single source of truth for all instrumentation decisions.
Key Decisions
Server-side GTM over client-side-only tagging
Server-side collection provides more reliable data, better privacy compliance, and resilience against ad blockers and browser restrictions.
- Client-side GTM only
- Direct API integrations without a tag manager
Governed tracking plan as a living document
A tracking plan that lives alongside the implementation prevents schema drift and gives the whole team a shared language for events and properties.
Tech Stack
- Segment
- Google Tag Manager (server-side)
- GA4
- Consent Mode v2
- Identity resolution
Result & Impact
Clean, governed event data flowing through a unified CDP. Marketing and analytics teams share a single source of truth for tracking decisions, and new instrumentation follows a documented process.
Learnings
- A tracking plan is a governance document, not a spreadsheet — it needs ownership, review cycles, and versioning
- Identity resolution is the hardest part of CDP work and deserves dedicated architecture time
Full case study in progress.