Full-Stack Analytics Pipeline & Governance: Buendía Tours

Google Tag ManagerGA4BigQueryOneTrustDrupalJavaScriptData EngineeringAnalyticsPrivacyGDPR

The Challenge

Buendía Tours needed to move beyond basic reporting to a sophisticated, data-driven marketing strategy. The primary hurdles were a lack of raw data access for deep analysis, inconsistent event tracking across their Drupal-based site, and the urgent need to comply with stringent EU privacy regulations (GDPR) without losing marketing visibility.


The Tech Stack

Data Collection

Google Tag Manager (GTM), JavaScript

Analytics & Storage

GA4, BigQuery (SQL)

Privacy & Consent

OneTrust

CMS

Drupal


The Solution

End-to-End ETL Orchestration

Designed the automated pipeline to flow from the browser to BigQuery. By bypassing the limitations of the GA4 UI, I enabled the team to perform complex SQL-based attribution modeling and lifetime value (LTV) analysis.

Automated Event Framework

Instead of manual tagging for every new tour or landing page, I engineered a dynamic framework between the Drupal backend and GTM. This utilized a standardized dataLayer schema that auto-populated event parameters based on site metadata.

Privacy-First Governance

Authored a comprehensive Data Governance guide and integrated OneTrust consent signals directly into GTM. This ensured that tracking only fired when legal consent was present, protecting the brand from compliance risks.


The "Aha!" Moment

By centralizing the data in BigQuery, we were able to join website behavior with booking data. We discovered that a significant portion of "lost" conversions weren't due to price, but due to users checking the "meeting point" maps on mobile and getting lost in a navigation loop. This insight allowed the team to prioritize a UI fix for the map integration.

The Business Impact

80% faster

Implementation Velocity — reduction in time to deploy new tracking events through the automated framework

Real-time

Data Accessibility — enabled real-time marketing attribution dashboards, allowing budget to shift to high-performing channels instantly

100%

Regulatory Compliance — alignment with GDPR standards through the OneTrust/GTM integration

Zero tags

Technical Debt Reduction — eliminated hard-coded tags, creating a clean, maintainable GTM container