Inventory the legacy estate: schemas, objects, ETL jobs, Alteryx workflows, stored logic, reports and consumers.
parse Alteryx workflows to extract embedded business logic.
Build the dependency map
Rebuild logic as tested Dataform models on silver/gold.
Migrate historical data with row-count, sum and sample-record reconciliation;
Document legacy defects discovered during migration and escalate for a business decision rather than silently correcting them.
Produce the decommissioning plan for the legacy DWH and workflows, and the legacy migration record for handover.
Required skills and experience
6+ years in data warehouse migration and ETL modernisation.
Expert SQL across at least two of SQL Server / Oracle / Teradata / PostgreSQL, including stored-procedure logic archaeology.
Hands-on Alteryx Designer: reading, documenting and re-expressing workflow logic in SQL. This is the scarcest skill in the team — confirm availability early.
Reconciliation technique: designing tolerance-based comparison of legacy and target outputs and defending results at acceptance.
BigQuery target-side development (Dataform or dbt).
The judgement to argue for retirement rather than migration where usage analysis supports it.
Certifications
Preferred: Alteryx Designer Core/Advanced; Google Cloud Professional Data Engineer.