A structured approach to investigating reporting differences across GA4, Google Ad Manager, Parse.ly, and BigQuery.
GA4Google Ad ManagerBigQueryPythonData QA
My role
Data Analyst
Scope
Data quality and reporting
Status
Ongoing practice
Challenge
Different tools can legitimately report different numbers.
Digital analytics platforms measure data at different times and through different definitions. When stakeholders need trusted reporting, those differences must be investigated, documented, and resolved where appropriate.
Approach
Trace a discrepancy from definition to source data.
01
Align the question
Confirm the reporting period, metric definition, filters, and expected source of truth.
02
Compare the data path
Use SQL and platform-level checks to trace data from source systems through BigQuery datasets and reports.
03
Validate the fix
Apply QA checks and automation where useful, then communicate the reason for the difference clearly.
Outcome
More confidence in cross-platform reporting.
This work helps maintain trusted reporting across the analytics stack by turning unexplained differences into testable data-quality questions. Client data, internal schemas, and results are intentionally not published.