ETL Tester (Contract)

Toronto, ON
Hybrid
Posted Sep 30, 2026
1 position

Opens an external site

Employment type: Contract, Full-time
Experience level: Senior · 5+ years
Posting language: English
Working hours: 40 hours per week
Office presence: 4 days per week

Job summary

Collaborate with cross-functional teams to troubleshoot data quality issues and validate ETL workflows across various platforms. Manage the end-to-end testing lifecycle, including test planning, execution, and reporting for data warehouse initiatives.

Job details

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.

What you’ll do

Requirements

Requires 5+ years of hands-on experience in ETL testing, data validation, and source-to-target reconciliation within data warehouse environments. Proficiency in SQL, Python, and major data platforms like BigQuery, Oracle, and Informatica is essential.