ETL Tester (Contract)

Downtown Toronto (Toronto Dominion Centre / Design Exchange)

State/Province Ontario

M5K

Job Description

CoreFactor is searching for an ETL Tester on a contract basis for a Financial Services client in the GTA .

This position is hybrid and will require the successful incumbent to go into the office four (4) days per week.

Roles and Responsibilities

• Collaborate with developers, business analysts, data engineers, and other stakeholders to identify, troubleshoot, and resolve data quality issues.
• Participate in requirements reviews, source-to-target mapping sessions, and design discussions to ensure testability, completeness, and data quality.
• Analyze source-to-target mappings, define test strategies, create comprehensive test cases, and perform rigorous data validation.
• Validate data accuracy, completeness, and integrity through source-to-target reconciliation and transformation testing.
• Execute complex SQL queries, perform backend testing, and validate ETL transformations across Oracle, SQL Server, and BigQuery platforms.
• Validate end-to-end ETL workflows, data pipelines, and data movement across source, staging, and target environments.
• Work with multiple source systems containing structured, semi-structured, and JSON data.
• Develop and maintain automated data validation, reconciliation, and regression tests using Python, SQL, and other automation utilities.
• Support continuous improvement of ETL testing processes through automation and reusable testing frameworks.
• Own test planning, test execution, defect management, regression validation, test reporting, and testing sign-off for assigned EDW initiatives.
• Collaborate with project teams to support release readiness activities and ensure delivery quality.
• Maintain test cases, test results, defect logs, and other QA artifacts in Jira, Confluence, and related project repositories.

Requirements

• 5+ years of hands‑on experience in ETL testing, data validation, source‑to‑target reconciliation, data transformation testing, and end‑to‑end validation of data pipelines in Data Warehouse environments.
  
• Strong experience with SQL, backend testing, ETL validation, and complex BigQuery queries for data validation, reconciliation, and troubleshooting.
  
• Strong understanding of Data Warehousing concepts, ETL processes, data modeling, and data quality principles.
  
• Hands‑on experience with Oracle, SQL Server, BigQuery, Informatica PowerCenter, Airflow/Cloud Composer, and GCP data services.
  
• Experience validating data across source, staging, and target systems, including structured, semi‑structured, and JSON data.
  
• Experience developing and maintaining ETL test automation solutions using Python, SQL, or similar technologies for automated data validation, reconciliation, and regression testing.
  
• Proven ability to own test planning, test execution, regression validation, defect management, and testing sign-off activities for EDW initiatives.